Chapter X: Front Matter (10)

_Polycyrtida_, Haeckel, 1862, Monogr. d. Radiol., p. 341.
_Polycyrtida_, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p.
519.
_Botryodea_ (= _Botrida_ vel _Botryida_), Haeckel, 1881, Prodromus, p.
439.

_Definition._--NASSELLARIA with a complete lattice-shell, exhibiting constantly a lobate and multilocular cephalis, with three to five or more separated lobes, and two to three or more constrictions.

The suborder #Botryodea# differs from the other #Cyrtellaria# in the multilocular and lobate shape of the cephalis, which is composed of at least three or four, often five or six, and sometimes even a greater number of lobes, which are separated by constrictions and partly also by internal septa. This characteristic shape is found neither in the #Spyroidea# (with bilocular cephalis) nor in the #Cyrtoidea# (with simple cephalis). The affinities of the former group to the two latter form a very complicated problem, which is not yet solved; the morphology of the #Botryodea# is the most difficult part in the system of NASSELLARIA, and what we can here give, are incomplete and unsatisfactory beginnings only.

Up to the year 1860 only a single genus of the #Botryodea# was known, _Lithobotrys_, one of the oldest genera of "_Polycystina_," and described by Ehrenberg in 1844 (Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 74). He gave the following definition:--"Loricæ siliceæ articuli in adulto non in seriem, sed in uvæ brevis formam, id est in loculos plus minus discretos nonnullos contiguos dispositi. Proxime ad Lithocampem accedit." In his first System (1847) _Lithobotrys_ is placed with _Lithocampe_ among his family Lithochytrina. Afterwards (1860) Ehrenberg added two new genera, under the names _Botryocampe_ and _Botryocyrtis_ and figured some species of these incompletely in his last works (1872, 1875).

In my Monograph I founded for these three genera the separate subfamily of Polycyrtida, added as a fourth genus _Spyridobotrys_, and gave to the group the following definition (1862, loc. cit., p. 341):--"Lattice-shell divided by two or more annular strictures, partly longitudinally, partly transversely, into three or more unequal chambers, which are placed in different planes and have a different relation to the poles of the shell-axis."

The new and remarkable forms of #Botryodea#, which I subsequently found in the Challenger collection, demonstrated that the #Botryodea# differ from the other #Cyrtellaria# (the #Cyrtoidea# as well as the #Spyroidea#) in a far higher degree than I formerly had supposed. A synopsis of the figures in Pl. 96 will give sufficient evidence of this view. Therefore in my Prodromus (1881, p. 439) {1104}I completely separated the #Botryodea# (or Botrida) from the other suborders of #Cyrtellaria# (Spyrida and Cyrtida).

Bütschli gave, in 1882, in his paper on the Cyrtida (_loc. cit._) a very accurate description of _Lithobotrys geminata_, and pointed out its close affinity to _Lithocorythium_ and _Lithomelissa_, and the importance of an oblique septum separating the cephalis into a smaller anterior and a larger posterior lobe. His views on the #Botryodea# (as a subordinate group of the #Cyrtoidea#) are however incomplete, since the peculiar forms, described in the following pages, were unknown to him.

According to the wide morphological divergence of the different #Botryodea#, and the numerous peculiar forms developed from it, we here divide the whole group into three families and ten genera, with fifty-five species. These form, however, only a small part of the large and varied mass of closely related forms which are found in the rich collections of the Challenger. The great difficulty of researches on their intimate structure, and the great amount of time required for it, prevented me from giving a more complete and exact description than the one here given. The observation of the small shells from all the different sides is a difficult task, requiring years of work, and its satisfactory explanation would be possible only by means of numerous figures.

The three families of #Botryodea#, here described, correspond to the three first groups of #Cyrtoidea#. The first family, Cannobotryida, corresponds to the Monocyrtida clausa and to the Zygospyrida; their shell consists of a cephalis only, without subsequent joints. The second family, Lithobotryida, corresponds to the Dicyrtida and Phormospyrida; their shell is composed of a cephalis and a thorax, both joints being separated by a transverse cortinar septum and a collar stricture. The third family, Pylobotryida, has a three-jointed shell, like the Tricyrtida, with cephalis, thorax and abdomen.

The cephalis is the most characteristic part of the shell of the #Botryodea# and its lobulate and multilocular shape separates them from the #Spyroidea# and #Cyrtoidea#. It represents the whole shell in the Cannobotryida, and in the young state of the two other families, which afterwards develop a thorax (Lithobotryida) and an abdomen (Pylobotryida). The typical lobulation of the cephalis is probably originally caused by internal septa; and these may be originated by branches of the internal columella, which corresponds either to the central ascending columella of the #Plectoidea# or to the excentric ascending dorsal rod of the sagittal ring of the #Stephoidea#. But afterwards, when the original septa disappear and are lost by reduction, only the external constrictions remain to indicate the limits of the single lobes.

Among the internal septa and the corresponding external constrictions which effect the lobulation of the cephalis, may be distinguished primary or constant septa and secondary or inconstant septa. As primary septa we regard firstly an oblique frontal {1105}septum and secondly a vertical sagittal septum. The frontal septum (described accurately by Bütschli) has usually two or three pairs of pores and ascends obliquely from the base to the anterior face of the cephalis, where it is inserted in the orbital region; it divides the cephalis into a smaller anterior or facial lobe and a larger posterior or occipital lobe. The latter is commonly higher and more developed than the former and partly covers its upper face, like the crest of a helmet. The facial lobe is again bisected by an incomplete sagittal septum and a corresponding partial constriction on the anterior face. We find, therefore, in this original cephalis of the #Botryodea#, three primary lobes, an odd larger occipital lobe and two paired smaller facial lobes. The typical trilobed cephalis may be regarded perhaps as the common original form of the #Botryodea#.

The secondary and inconstant constrictions which we find in many #Botryodea#, and which produce a greater number of lobes in the cephalis, require further accurate observation. The following cases of lobation may be considered as the most important:--(1) Cephalis with four lobes, opposite in two pairs (two larger occipital and two smaller facial lobes, separated by a complete sagittal and an oblique frontal constriction); (2) cephalis with four unequal lobes, two of which are odd and sagittal, two paired and lateral (the odd occipital lobe usually larger and the odd mandibular lobe smaller than the two paired lateral or buccal lobes); (3) cephalis with five lobes (a large odd occipital lobe and two pairs of smaller lobes, anterior nasal, and lateral buccal lobes); (4) cephalis with five lobes, three of which are odd (a posterior occipital, middle frontal, and anterior facial lobe), and one pair of lateral lobes; (5) cephalis with six lobes, opposite in pairs (two larger occipital, two smaller nasal and two intermediate lateral or buccal lobes); (6) cephalis with six lobes, two of which are odd and sagittal (a large occipital and a smaller nasal lobe), four opposite in pairs (two anterior and two posterior buccal lobes); (7) cephalis with seven lobes, three of which are odd (a large posterior occipital, a middle frontal, and an anterior small nasal lobe), four opposite in two pairs (an anterior buccal and a posterior temporal pair); (8) cephalis with eight lobes, two of which are odd (a large posterior occipital and a small anterior frontal lobe) and six opposite in three lateral pairs; (9) cephalis with nine lobes, three of which are odd (an occipital, a frontal and a nasal lobe) and six opposite in three lateral pairs; (10) cephalis with ten lobes, two of which are odd (a large occipital and a smaller frontal lobe) and the other eight opposite in pairs; (11) cephalis with numerous lobes (twelve to fifteen or more) which are symmetrically disposed on each side of the median plane; (12) cephalis with numerous lobes (twelve to fifteen or more) which are irregularly and sometimes spirally conglomerated.

All these different forms of lobation require a far more thorough examination than I can devote to them, and may furnish examples of regular laws of development. The irregular forms are rather common, and I have found some very irregular #Botryodea# {1106}(not here described) in which I could not determine the topographical regions of the cephalis. The difficulty in the examination of these complicated forms is increased by their very small size, which does not reach the usual dimensions of the other #Cyrtellaria#. In some cases I was able to observe on the base of the cephalis the same typical cortinar pores (in two or three pairs), which we also find in the same part of the cephalis in the #Spyroidea# and #Cyrtoidea#, and which are inherited from the Semantida.

The thorax of the #Botryodea#, or the second shell-joint, absent in the Cannobotryida, is usually of very simple form, ovate, truncate, conical or cylindrical, and consists of a secondary joint, developed from the base of the cephalis. The thorax is usually small, about the same size as the cephalis or a little larger, whilst in the #Cyrtoidea# it is commonly much larger than the latter. Its terminal mouth is closed by a lattice-plate in the Botryocellida, while it remains open in the Botryopylida and Pylobotryida.

The abdomen, or the third shell-joint, developed in the Pylobotryida only, generally also exhibits a very simple shape, like the thorax, and it is a tertiary joint developed from the base of the thorax. It exhibits to the latter the same relation as in the Tricyrtida. The terminal mouth of the abdomen remains open in the Botryocyrtida; it becomes closed by a lattice-plate in the Botryocampida.

The lattice-plate forming the shell of the #Botryodea# is usually very thin and fragile, with very small circular pores. These are often very numerous, at other times scarce, and sometimes nearly wanting, so that the shell appears hyaline. In this group there never occurs that great variety in form and size of the pores, which numerous #Cyrtoidea# and #Spyroidea# exhibit.

The radial apophyses which are found in the majority of #Botryodea# seem to correspond in position and relation to the typical radial beams of the other NASSELLARIA, viz., three descending basal feet arising from the base of the cephalis, and an ascending vertical apical horn arising from the top of the cephalis. Here also they seem to be inherited from the #Plectoidea# or #Stephoidea# (_Cortina_, _Cortiniscus_). But whilst these four typical radial beams in the other NASSELLARIA are usually simple spines or solid rods, here they usually appear as hollow cylindrical tubes, the thin wall of which is pierced by the same small pores as the shell. These porous tubes are either straight or slightly curved, often inflated and ovate at the base. We find in their number and disposition the same variety as in the simple radial spines of the other NASSELLARIA. The original number may here also be seen in the development of four typical beams, an ascending apical tube on the top of the cephalis, and three descending basal tubes on its base; the odd posterior tube of the latter corresponds to the caudal foot, the two paired anterior to the pectoral feet. There is often also a fourth foot developed opposite to the caudal, and representing a sternal tube. Sometimes also two superior tubes are developed, a posterior occipital and an anterior frontal. The different {1107}apophyses may be lost by reduction. I have never observed #Botryodea# with more than five apophyses.

_The Central Capsule_ of the #Botryodea# is not yet sufficiently known, no living species having been observed. In some preparations from specimens in the Challenger collections, stained by Dr. John Murray with carmine immediately after the dredging operation, single #Botryodea# are to be found in which the central capsule is deeply coloured. In _Botryopera quinqueloba_ (Pl. 96, fig. 2) it filled up the greater part of the cephalis and seemed to be divided into some small lobes. In _Lithobotrys sphærothorax_ (Pl. 96, fig. 15) it was divided into four lobes, three of which filled the trilobed cephalis, the fourth large lobe occupying a great part of the spherical thorax. Details of their structure, unfortunately, were not recognisable. There can, however, be no doubt that they are the same as in all other NASSELLARIA.

_Synopsis of the Families of_ #Botryodea#.

1. Shell monothalamous, consisting of the lobate
cephalis only, 1. CANNOBOTRYIDA.

2. Shell dithalamous, composed of a lobate cephalis
and a simple thorax, 2. LITHOBOTRYIDA.

3. Shell trithalamous, composed of a lobate cephalis,
a thorax and an abdomen, 3. PYLOBOTRYIDA.

Family LVI. #CANNOBOTRYIDA#, Haeckel (_sensu emendato_).

_Cannobotryida_, Haeckel, 1881, Prodromus, p. 440.

_Definition._--Botryodea monothalamia, the shell of which represents a lobate cephalis, without thorax and abdomen.

The family #Cannobotryida# (retained here with a stricter definition than originally was given in my Prodromus) comprises those #Botryodea#, in which the whole shell is represented by the cephalis alone, without thorax and abdomen. Since the two latter joints, found in the two following families, are secondary productions, the Cannobotryida must be regarded as the ancestral forms of all #Botryodea#, in an ontogenetic as well as in a phylogenetic sense.

Two species only of this family have been hitherto known, incompletely described by Ehrenberg as _Lithobotrys triloba_ and _Lithobotrys quadriloba_. A great number of similar forms are to be found in the Radiolarian ooze of the Central Pacific, but they are very minute, and difficult to examine. We can describe here only twelve species of these, which we arrange in two genera; _Botryopera_ without porous tubes, and _Cannobotrys_ bearing a variable number of porous cylindrical tubes (one to five). The number of lobes of the cephalis is also variable in each genus (one to five or more). If in the future these minute and interesting shells should be better examined, it would {1108}be advisable to distinguish a number of genera according to the different number of the porous tubes and of the lobes of the cephalis. The base of the latter is constantly closed by a basal lattice-plate, and usually exhibits two or three pairs of cortinar pores, identical with those of the Semantida.

The phylogenetic origin of the Cannobotryida may be found either in the Zygospyrida or in the Monocyrtida; they differ from these two similar groups in the lobation of the cephalis, which is effected by the development of internal septa and external constrictions.

_Synopsis of the Genera of Cannobotryida._

Cephalis without porous tubes, 486. _Botryopera_.

Cephalis with a variable number of porous tubes, 487. _Cannobotrys_.

Genus 486. _Botryopera_,[104] n. gen.

_Definition._--#Cannobotryida# without tubes on the cephalis.

The genus _Botryopera_ is the simplest form among the #Botryodea#, the shell consisting of a lobate cephalis only, without tubes or radial appendages. It may be derived either from _Dictyospyris_ or from _Archicapsa_ by development of the horizontal fold in the frontal face of the shell, and the corresponding internal frontal septum, which separates the larger occipital lobe from the smaller facial half; the latter may be divided again into paired frontal lobes, lateral buccal lobes, &c. _Botryopera_ may be the common ancestral form of many #Botryodea#.

1. _Botryopera cyrtoloba_, n. sp. (Pl. 96, fig. 1).

Cephalis trilobate; the posterior odd occipital lobe helmet-shaped, about twice as large as the two paired anterior frontal lobes, which are subovate and covered by the upper half of the former. Pores small and numerous, subregular, circular; some larger pores at the base.

_Dimensions._--Length of the shell 0.08, basal breadth 0.06.

_Habitat._--Central Pacific, Station 265 to 274, depth 2350 to 2925 fathoms.

2. _Botryopera triloba_, Haeckel.

_Lithobotrys triloba_, Ehrenberg, 1854, Mikrogeol., Taf. xxii. fig. 30.

Cephalis trilobate; the occipital lobe subcylindrical, one and a half times as long as the two frontal lobes, which are slender, ovate and not covered by the former. Pores small and numerous.

_Dimensions._--Length of the shell 0.05, breadth 0.03.

_Habitat._--Fossil in Tertiary rocks of the Mediterranean (Sicily, Greece, &c.)

{1109}3. _Botryopera quadriloba_, Haeckel.

_Lithobotrys quadriloba_, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, p. 84.

Cephalis quadrilobate; the occipital lobe helmet-shaped, one and a half times as long as the two paired hemispherical buccal lobes, and twice as large as the anterior frontal lobe. Pores not numerous, rather large, circular.

_Dimensions._--Length of the shell 0.06, breadth 0.04.

_Habitat._--Fossil in Barbados and North America (Virginia).

4. _Botryopera quinqueloba_, n. sp. (Pl. 96, fig. 2).

Cephalis quinquelobate; the occipital lobe helmet-shaped, and twice as long as the two hemispherical frontal lobes, three times as long as the subspherical lateral buccal lobes. Pores scarce, small, circular.

_Dimensions._--Length of the shell 0.07, basal breadth 0.05.

_Habitat._--North Pacific, Station 253, depth 3125 fathoms.

5. _Botryopera multiloba_, n. sp.

Cephalis multilobate; the posterior odd occipital lobe ovate, and of about the same size as the anterior frontal half of the shell, which is clustered and divided into five to seven smaller lobes, an odd subspherical sternal lobe, and on each side of it two or three pairs of smaller subspherical lobes.

_Dimensions._--Length of the shell 0.09, breadth 0.06.

_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.

Genus 487. _Cannobotrys_,[105] Haeckel, 1881, Prodromus p. 440.

_Definition._--#Cannobotryida# with tubes on the cephalis.

The genus _Cannobotrys_ differs from the preceding _Botryopera_ in the development of hollow radial tubes, arising from the lobate cephalis in various numbers. According to their number the genus may be divided into various subgenera: (1) _Cannobotrantha_ (_monocanna_) with a single apical tube; (2) _Cannobotrella_ (_dicanna_) with two divergent tubes, an ascending apical and a descending sternal one; (3) _Cannobotrissa_ (_tricanna_) with three tubes in the sagittal plane (an upper apical, a posterior caudal, and an anterior sternal); (4) _Cannobotromma_ (_tetracanna_) with four radial tubes disposed like the four typical spines of _Cortina_ (compare p. 950), and _Cannobotrusa_ (_pentacanna_) with five radial tubes disposed like the five typical spines of _Stephanium_ (p. 952). {1110}Perhaps these five groups may be separated as five genera, possessing near relations to five very different genera of NASSELLARIA (_Circospyris_, _Halicapsa_, _Archibursa_, _Cortina_, _Stephanium_, &c.)

1. _Cannobotrys monocanna_, n. sp.

Cephalis trilobate, with a single cylindrical straight apical tube on the apex of the occipital lobe, which is helmet-shaped, and about one and a half times as long as the two subspherical frontal lobes. Pores small and numerous, subregular, circular.

_Dimensions._--Length of the shell 0.05, breadth 0.03.

_Habitat._--Tropical Atlantic, Station 347, depth 2250 fathoms.

2. _Cannobotrys dicanna_, n. sp.

Cephalis quadrilobate, with two divergent tubes, an odd apical tube on the apex of the posterior occipital lobe, and an odd sternal tube on the anterior frontal lobe. Between these two odd lobes lie two paired lateral or buccal lobes, of about the same size. Shell nearly hyaline, with very few minute pores.

_Dimensions._--Length of the shell 0.06, breadth 0.04.

_Habitat._--Indian Ocean; Madagascar (Rabbe), surface.

3. _Cannobotrys tricanna_, n. sp. (Pl. 96, fig. 3).

Cephalis quinquelobate, with three curved cylindrical tubes in the sagittal plane; an ascending apical tube on the apex of the helmet-shaped occipital lobe, and two horizontal tubes on the base of the shell (a posterior caudal, _c_, and an anterior sternal, _z_). The two frontal lobes are hemispherical, and twice as large as the two lateral buccal lobes. Pores very small and numerous.

_Dimensions._--Length of the shell 0.08, basal breadth 0.06.

_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.

4. _Cannobotrys sagittalis_, n. sp.

Cephalis multilobate, with three straight divergent cylindrical tubes in the sagittal plane; a vertical apical tube on the apex of the ovate occipital lobe, and two horizontal tubes on the base, as in the preceding similar species; it differs from the latter in the greater number of lobes (seven or nine), the two frontal lobes being divided into two or four secondary lobules.

_Dimensions._--Length of the shell 0.1, breadth 0.07.

_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.

5. _Cannobotrys cortina_, n. sp. (Pl. 96, fig. 4).

Cephalis quinquelobate, with four cylindrical nearly straight tubes of equal size; an ascending, nearly vertical, apical tube on the apex of the occipital lobe, and three divergent descending tubes {1111}on the base of the shell (an odd posterior caudal tube and two paired anterior pectoral tubes). The two lateral buccal lobes are twice as large as the two anterior frontal lobes, and half as large as the posterior odd occipital lobe. The four tubes in this and the following species correspond probably to the four spines of _Cortina_ (p. 950).

_Dimensions._--Length of the shell 0.07, basal breadth 0.06.

_Habitat._--Central Pacific, Stations 263 to 274, depth 2350 to 2925 fathoms.

6. _Cannobotrys tetracanna_, n. sp.

Cephalis multilobate, with four cylindrical curved tubes conical at their wider base, corresponding to those of the preceding species and to the four spines of _Cortina_. The odd occipital lobe is of about the same size as the anterior part of the shell, which is cleft into three pairs of roundish lobes, one pair of anterior larger frontal lobes, and two pairs of smaller lateral buccal lobes. Pores very few and minute.

_Dimensions._--Length of the shell 0.11, basal breadth 0.07.

_Habitat._--North Pacific, Station 253, depth 3125 fathoms.

7. _Cannobotrys pentacanna_, n. sp.

Cephalis quinquelobate, with five cylindrical slender curved tubes, three of which are placed in the sagittal plane (a superior apical, a posterior caudal, and an anterior sternal), whilst the other two are paired and diverge laterally (two pectoral tubes). The five tubes correspond exactly to the five typical spines of _Stephanium_ (p. 952). The helmet-shaped occipital lobe of the shell is twice as large as each of the two anterior frontal lobes, and three times as large as each of the two lateral buccal lobes. Pores numerous.

_Dimensions._--Length of the shell 0.07, basal breadth 0.04.

_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.

Family LVII. #LITHOBOTRYIDA#, n. fam.

_Definition._--Botryodea dithalamia, the shell of which is composed of a lobate cephalis and a simple thorax, without abdomen.

The family #Lithobotryida# comprises those #Botryodea# in which the shell is divided by a transverse annular constriction into a lobate cephalis and a simple thorax. They correspond therefore to the Dicyrtida among the #Cyrtoidea#, and to the Phormospyrida among the #Spyroidea#. The thorax, or the second shell-joint, is in all these three families a secondary production, arising from the base of the cephalis; therefore the Lithobotryida must be phylogenetically derived from the Cannobotryida.

Several species of _Lithobotrys_ were first described by Ehrenberg as _Lithobotrys_ and _Lithocorythium_. These two genera are, however, identical, as has been {1112}demonstrated by Bütschli (1882, _loc. cit._, p. 519). Some other species united by Ehrenberg with _Lithobotrys_ belong to other genera. The number of Lithobotryida found in the "Radiolarian ooze" of the Challenger collection, is far greater than that of the Cannobotryida and Pylobotryida. But only a small part of them could be thoroughly examined and described here, so that their number may be greatly augmented by further accurate researches. We here arrange those forms in four genera, representing two different subfamilies. The terminal mouth of the thorax remains open in the Botryopylida, whilst it becomes closed by a lattice-plate in the Botryocellida. In each group there are shells with and without porous tubes. The number of these tubes, and also the number of lobes of the cephalis, is very variable, and may in future serve for the distinction of more genera.

_Synopsis of the Genera of Lithobotryida._

{Cephalis without porous
I. Subfamily Botryopylida. { tubes, 488. _Botryopyle_.
{
Mouth of the thorax open. {Cephalis with a
{ variable number of
{ porous tubes, 489. _Acrobotrys_.

{Cephalis without
II. Subfamily Botryocellida. { porous tubes, 490. _Botryocella_.
{
Mouth of the thorax closed {Cephalis with a
by a lattice-plate. { variable number of
{ porous tubes, 491. _Lithobotrys_.

Genus 488. _Botryopyle_, Haeckel, 1881, Prodromus, p. 440.

_Definition._--#Lithobotryida# without tubes on the cephalis, and with the mouth of the thorax open.

The genus _Botryopyle_ comprises the simplest forms of Lithobotryida, the lobate cephalis bearing no tubes and the basal mouth of the thorax remaining open. It may be derived either from _Dictyocephalus_ or from _Desmospyris_, by development of lobes on the cephalis and of an internal frontal septum, separating the larger occipital lobe from the smaller frontal half of the shell. The latter may be divided again into anterior frontal lobes, lateral buccal lobes, &c.

1. _Botryopyle sethocorys_, n. sp. (Pl. 96, fig. 7).

Cephalis trilobate, separated by a deep collar constriction from the hemispherical thorax, which is twice as broad. Occipital lobe helmet-shaped, little longer than the two hemispherical frontal lobes. Surface spiny. Pores irregular, roundish, of very different size.

_Dimensions._--Length of the shell 0.1, breadth 0.07.

_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.

{1113}2. _Botryopyle cribrosa_, Haeckel.

_Lithobotrys cribrosa_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 76, Taf. iii. fig. 20.

? _Lithobotrys biceps_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 295, Taf. ix. fig. 23.

Cephalis trilobate, separated by a slight collar constriction from the ovate thorax, which is somewhat smaller. Occipital lobe very large, helmet-shaped, longer than the thorax and twice as long as the two subspherical frontal lobes. Pores regular, circular, scarce.

_Dimensions._--Length of the shell 0.11, breadth 0.05.

_Habitat._--Fossil in Barbados.

3. _Botryopyle cephalodes_, Haeckel.

_Lithocorythium cephalodes_, Ehrenberg, 1875, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 78, Taf. iv. fig. 6.

Cephalis quinquelobate, separated by a slight collar constriction from the larger conical thorax, which is gradually dilated towards the wide mouth. Occipital lobe helmet-shaped, little longer than the frontal half of the cephalis, which is divided into two pairs of lateral chambers, corresponding to the four crossed pores of the sagittal septum, figured by Ehrenberg. The figure of the latter is inverse, seen from the frontal face, a part of the frontal wall having been broken off.

_Dimensions._--Length of the shell 0.08, breadth 0.05.

_Habitat._--Fossil in Barbados.

4. _Botryopyle dictyocephalus_, n. sp. (Pl. 96, fig. 6).

Cephalis multilobate, separated by an oblique constriction from the subcylindrical thorax, which is somewhat larger and slightly curved. Occipital lobe conical, of the same length as the posterior part of the triangular frontal half of the shell, which is divided into five to seven lobes, two or three odd lobes in the median part, and one or two pairs of lateral lobes; very variable in size and form of the lobes. Mouth of the thorax wide, truncate.

_Dimensions._--Length of the shell 0.12, breadth 0.07.

_Habitat._--Central Pacific, Station 271 to 274, depth 2350 to 2750 fathoms.

5. _Botryopyle inclusa_, n. sp. (Pl. 96, fig. 5).

Cephalis multilobate, campanulate, separated by a sharp constriction from the inflated thorax, which is nearly twice as long and broad. Both joints of the shell are irregularly lobate, with numerous vaulted lobes of different sizes, and partly internal septa. Pores small and numerous.

_Dimensions._--Length of the shell 0.1, breadth 0.06.

_Habitat._--Mediterranean (Candia), Spratt, depth 1620 fathoms.

{1114}Genus 489. _Acrobotrys_, Haeckel,[106] 1881, Prodromus, p. 440.

_Definition._--#Lithobotryida# with tubes on the cephalis, and with the mouth of the thorax open.

The genus _Acrobotrys_ differs from the preceding _Botryopyle_ in the development of radial tubes, and from its probable ancestral form, _Cannobotrys_, in the development of a thorax, the basal mouth of which remains open. According to the varying number of the tubes we may distinguish the following five subgenera (corresponding to those of _Cannobotrys_), viz., (1) _Acrobotrantha_ (_monosolenia_) with a single (apical) tube; (2) _Acrobotrella_ (_disolenia_) with two divergent tubes (an apical and a sternal); (3) _Acrobotrissa_ (_trisolenia_) with three sagittal tubes (an apical, a caudal, and a sternal); (4) _Acrobotromma_ (_tetrasolenia_) with four tubes, like the four typical spines of _Cortina_; and (5) _Acrobotrusa_ (_pentasolenia_) with five feet, corresponding to the five typical spines of _Stephanium_.

1. _Acrobotrys monosolenia_, n. sp.

Cephalis trilobate, with a single straight apical tube, which ascends vertically from the apex of the occipital lobe, and is pointed at the distal end, with an anterior oblique aperture. Two frontal lobes paired, ovate, half as long as the helmet-shaped occipital lobe. Thorax ovate, twice as long as the cephalis. Pores very scarce.

_Dimensions._--Length of the shell 0.08, breadth 0.06.

_Habitat._--Mediterranean (Corfu), surface.

2. _Acrobotrys disolenia_, n. sp. (Pl. 96, fig. 10).

Cephalis trilobate, with three odd ovate lobes of nearly equal size in the sagittal plane and two divergent straight slender cylindrical tubes, a vertical apical tube on the occipital lobe, and a horizontal nasal tube on the frontal lobe; the middle lobe between them is somewhat smaller. Thorax ovate, about twice as large as the cephalis, with constricted mouth. Pores small and numerous.

_Dimensions._--Length of the shell 0.1, breadth 0.06.

_Habitat._--Central Pacific, Station 265 to 274, depth 2350 to 2925 fathoms.

3. _Acrobotrys aquaria_, n. sp.

Cephalis quinquelobate, with two divergent long cylindrical curved tubes. Occipital lobe helmet-shaped, with an ascending apical tube; nasal lobe conical, with a descending sternal tube; {1115}between them a smaller odd middle lobe, and on each side of the latter an ovate frontal lobe. Thorax inflate, twice as long and broad as the cephalis. Pores small, scarce.

_Dimensions._--Length of the shell 0.09, breadth 0.07.

_Habitat._--South Pacific, Station 285, depth 2375 fathoms.

4. _Acrobotrys acuminata_, n. sp. (Pl. 96, fig. 9).

Cephalis sexlobate, with two divergent tubes. Occipital and frontal lobes ovate, odd; between them a cupola-shaped apical lobe, bearing an ascending pointed apical tube. On each side at the base a small buccal lobe, and between the paired buccal lobes an anterior nasal lobe with a descending curved sternal tube. Thorax smaller than the cephalis. Pores numerous and small.

_Dimensions._--Length of the shell 0.11, breadth 0.09.

_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.

5. _Acrobotrys auriculata_, n. sp. (Pl. 96, fig. 11).

Cephalis quadrilobate, with three pointed and auriculate tubes, two ascending apical (an anterior and a posterior) in the helmet-shaped occipital lobe, and a descending sternal tube on the base of the frontal lobe; between the lobes two lateral paired buccal lobes. Thorax campanulate, twice as broad as the cephalis. Pores rather large and numerous.

_Dimensions._--Length of the shell 0.1, breadth 0.08.

_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.

6. _Acrobotrys trisolenia_, n. sp. (Pl. 96, fig. 8).

Cephalis quadrilobate, with four odd lobes and three divergent curved tubes, an ascending apical tube in the conical occipital lobe, and two descending tubes on the anterior and posterior basal lobes; between these three lobes a small central lobe. Thorax ovate, about as large as the cephalis. Pores small and numerous.

_Dimensions._--Length of the shell 0.11, breadth 0.05.

_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.

7. _Acrobotrys tetrasolenia_, n. sp.

Cephalis trilobate, with four slender cylindrical tubes. Occipital lobe helmet-shaped, with an apical tube on the apex and a caudal tube on the base. Two frontal lobes ovate, prolonged into two paired pectoral tubes. The four tubes correspond in position to the four spines of Cortina. Thorax inflate, ovate, larger than the cephalis. Pores very scarce, rather large, irregular.

_Dimensions._--Length of the shell 0.08, breadth 0.05.

_Habitat._--North Pacific, Station 244, depth 2900 fathoms.

8. _Acrobotrys pentasolenia_, n. sp.

Cephalis quinquelobate, with five short conical tubes; three divergent odd tubes arise from three odd lobes; an apical from the occipital lobe, a posterior caudal from the suboccipital lobe, and an {1116}anterior sternal from the nasal lobe. Two paired lateral tubes arise from the base of two ovate frontal lobes. The five tubes correspond in disposition to the five spines of Stephanium. Thorax truncate. Pores small.

_Dimensions._--Length of the shell 0.12, breadth 0.09.

_Habitat._--Tropical Atlantic, Station 347, depth 2250 fathoms.

Genus 490. _Botryocella_,[107] Haeckel, 1881, Prodromus, p. 440.

_Definition._--#Lithobotryida# without tubes on the cephalis, and with the mouth of the thorax closed.

The genus _Botryocella_ differs from the closely allied _Botryopyle_ in having the mouth of the thorax closed, and may be derived from it by development of a lattice-plate, effecting this closure. It bears therefore the same relation to the latter that _Dicolocapsa_ has to _Dictyocephalus_.

1. _Botryocella nucula_, Haeckel.

_Lithobotrys nucula_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 76, Taf. iii. fig. 16.

_Lithobotrys adspersa_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 76, Taf. iii. fig. 15.

Cephalis trilobate; occipital lobe helmet-shaped, nearly twice as long as the two ovate frontal lobes. Thorax about as long as the cephalis. Pores very small and scarce.

_Dimensions._--Length of the shell 0.06, breadth 0.03.

_Habitat._--Fossil in Barbados.

2. _Botryocella borealis_, Haeckel.

_Lithobotrys borealis_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 294, Taf. ii. fig. 3.

Cephalis trilobate; occipital lobe ovate, little longer than the two ovate frontal lobes. Thorax about twice as long as the cephalis. Pores very numerous and small.

_Dimensions._--Length of the shell 0.08, breadth 0.04.

_Habitat._--North Atlantic, Greenland, depth 1000 to 2000 fathoms.

3. _Botryocella tricellaris_, n. sp.

Cephalis trilobate, with three odd sagittal lobes; the middle or central lobe larger than the anterior frontal and smaller than the posterior occipital lobe. Thorax nearly spherical, about as long as the cephalis. Pores small and scarce.

_Dimensions._--Length of the shell 0.08, breadth 0.06.

_Habitat._--North Atlantic, Station 353, depth 2965 fathoms.

{1117}4. _Botryocella quadricellaris_, n. sp. (Pl. 96, fig. 13).

Cephalis quadrilobate; the helmet-shaped occipital lobe twice as long as the two paired subspherical buccal lobes, and three times as long as the odd spherical frontal lobe. Thorax nearly spherical, about as long as the cephalis.

_Dimensions._--Length of the shell 0.1, breadth 0.05.

_Habitat._--Central Pacific, Station 272, depth 4475 fathoms.

5. _Botryocella quadrigemina_, n. sp. (Pl. 96, fig. 14).

Cephalis quadrilobate, with two pairs of lateral ovate lobes and complete sagittal constriction; the two occipital lobes nearly twice as large as the two frontal lobes. Thorax ovate, separated from the cephalis by a collar septum with four cortinar pores (fig. 14).

_Dimensions._--Length of the shell 0.09, breadth 0.06.

_Habitat._--Indian Ocean, Sunda Strait (Rabbe), surface.

6. _Botryocella multicellaris_, n. sp. (Pl. 96, fig. 12).

Cephalis multilobate; occipital lobe helmet-shaped, very large, about twice as long and broad as the frontal half of the shell, which is divided into six to eight small roundish clustered lobes. Thorax subspherical, of about the same size as the cephalis.

_Dimensions._--Length of the shell 0.1, breadth 0.05.

_Habitat._--South Pacific Station 297, depth 1775 fathoms.

Genus 491. _Lithobotrys_,[108] Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 74.

_Definition._--#Lithobotryida# with tubes on the cephalis, and with the mouth of the thorax closed.

The genus _Lithobotrys_, the oldest and first known of the #Botryodea#, was founded by Ehrenberg in 1844, and was one of his five oldest genera of Polycystina. It represented by itself the suborder #Botryodea# until the year 1860. The numerous species described by Ehrenberg belong to very different genera of #Botryodea#, and partly also of #Spyroidea#. Following Bütschli (1882) we retain here the name _Lithobotrys_ for those species, the type of which is _Lithobotrys geminata_. The genus _Lithocorythium_ of Ehrenberg is for the greater part identical with it. When in the preceding genus _Acrobotrys_ the mouth of the thorax becomes closed by lattice work, _Lithobotrys_ arises. In the latter as well as in the former the number of tubes on the cephalis is different, and may characterise different subgenera.

{1118}1. _Lithobotrys geminata_, Ehrenberg.

_Lithobotrys geminata_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 76, Taf. iii. fig. 19.

_Lithobotrys geminata_, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol.
xxxvi, p. 519, Taf. xxxiii. fig. 27, a to c.

? _Lithocorythium platylophus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 78, Taf. iv. fig. 5.

Cephalis trilobate, with a single apical tube in the apex of the helmet-shaped occipital lobe, which is one and a half times as long as the two subspherical frontal lobes. Thorax ovate, one and a half times as long as the cephalis, with few small pores in six to eight transverse rows.

_Dimensions._--Length of the shell 0.1, breadth 0.05.

_Habitat._--Fossil in Barbados.

2. _Lithobotrys lithocorythium_, Haeckel.

_Lithocorythium oxylophus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 78, Taf. iv. figs. 3, 4.

? _Lithopera oxystauros_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 78, Taf. iii. fig. 6.

Cephalis trilobate, with a single apical horn or a pointed tube in the apex of the helmet-shaped occipital lobe, which is a little longer than the two ovate frontal lobes. Thorax ovate, about as long as the cephalis, with very numerous and small pores.

_Dimensions._--Length of the shell 0.08, breadth 0.04.

_Habitat._--Fossil in Barbados.

3. _Lithobotrys nasuta_, Ehrenberg.

_Lithobotrys nasuta_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 76, Taf. iii. fig. 21.

Cephalis quadrilobate, with a single descending sternal or nasal tube on the base of the anterior or frontal lobe, which is half as long as the helmet-shaped occipital lobe and twice as large as the two lateral buccal lobes. Thorax ovate, twice as long as the cephalis. Pores rather large, circular.

_Dimensions._--Length of the shell 0.11, broad 0.05.

_Habitat._--Fossil in Barbados.

4. _Lithobotrys ornata_, Ehrenberg.

_Lithobotrys ornata_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 76, Taf. iii. fig. 18.

Cephalis quinquelobate, with two divergent ascending tubes, a posterior occipital and an anterior sternal or nasal tube. Occipital lobe campanulate, twice as large as the two frontal, and four times as large as the two buccal lobes. Thorax ovate, twice as long as the cephalis. Pores scarce and small. The specimen figured by Ehrenberg is very incomplete.

_Dimensions._--Length of the shell 0.09, breadth 0.05.

_Habitat._--Fossil in Barbados.

{1119}5. _Lithobotrys sphærothorax_, n. sp. (Pl. 96, fig. 15).

Cephalis trilobate, with two divergent cylindrical tubes, an ascending apical tube in the apex of the ovate occipital lobe, and a descending sternal or nasal tube in the campanulate frontal lobe; between the two lobes a smaller central lobe. Thorax spherical, twice as long as the latter. Pores very small, numerous.

_Dimensions._--Length of the shell 0.08, breadth 0.06.

_Habitat._--Western Tropical Pacific, Station 225, depth 4575 fathoms.

6. _Lithobotrys mascula_, n. sp. (Pl. 96, fig. 16).

Cephalis sexlobate, with two divergent cylindrical tubes, an ascending apical tube in the apex of the helmet-shaped occipital lobe and a descending sternal tube on the base, between the two kidney-shaped frontal lobes. The latter are half as large as the odd occipital lobe and of about the same size as the two inflated lateral buccal lobes, which are separated by a small odd nasal lobe.

_Dimensions._--Length of the shell 0.13, breadth 0.08.

_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.

7. _Lithobotrys orchidea_, n. sp. (Pl. 96, fig. 17).

Cephalis sexlobate, similar to the preceding species, but with five divergent and curved cylindrical tubes, which correspond to the five spines of _Stephanium_; an apical tube on the apex of the occipital lobe, a caudal tube on its base, a sternal tube between the two frontal lobes, and two paired pectoral tubes between the latter and the lateral buccal lobes. Pores small and scarce.

_Dimensions._--Length of the shell 0.12, breadth 0.06.

_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.

Family LVIII. #PYLOBOTRYIDA#, Haeckel (_sensu emendato_).

_Pylobotryida_, Haeckel, 1881, Prodromus, p. 440.

_Definition._--Botryodea trithalamia, the shell of which is composed of a lobate cephalis, a thorax, and an abdomen.

The family #Pylobotryida# comprises those #Botryodea# in which the shell exhibits two parallel transverse annular constrictions, and is divided by these into three successive joints, corresponding to the cephalis, the thorax, and the abdomen of the Tricyrtida. As in the latter, the abdomen is here also a later production, arising from the terminal mouth of the thorax; therefore the Pylobotryida must be derived phylogenetically from the Lithobotryida.

Two genera of Pylobotryida were incompletely described in 1860 by Ehrenberg, _Botryocyrtis_ and _Botryocampe_. We retain them here, with a stricter definition, however. Two other genera were added in my Prodromus--_Pylobotrys_ and _Phormobotrys_. {1120}The small number of species here enumerated may be easily increased, since numerous forms, belonging probably to this family, are not sufficiently known. Their study is, however, very difficult and requires accurate examination of the tiny shells from different sides.

The four genera of Pylobotryida, here described, represent two different subfamilies. The terminal mouth of the abdomen remains open in the Botryocyrtida, whilst it becomes closed by a lattice-plate in the Botryocampida. There are in both groups shells with and without porous tubes; the number of these tubes, and also the number and disposition of the lobes in the cephalis, exhibits remarkable differences in the different species of those genera, and may in future serve for their division into a greater number of genera.

_Synopsis of the Genera of Pylobotryida._

{ Cephalis without
I. Subfamily Botryocyrtida. { porous tubes, 492. _Botryocyrtis_.
{
Mouth of the abdomen open. { Cephalis with a
{ variable number of
{ porous tubes, 493. _Pylobotrys_.

{ Cephalis without
II. Subfamily Botryocampida. { porous tubes, 494. _Botryocampe_.
{
Mouth of the abdomen closed { Cephalis with a
by a lattice-plate. { variable number
{ of porous tubes, 495. _Phormobotrys_.

Genus 492. _Botryocyrtis_,[109] Ehrenberg, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 829.

_Definition._--#Pylobotryida# without tubes on the cephalis, and with the mouth of the abdomen open.

The genus _Botryocyrtis_, founded by Ehrenberg upon two Indian species, is the simplest among the Pylobotryida. It may have been derived from _Botryopyle_ by the development of an abdomen (or a third shell-joint), the mouth of which remains open.

1. _Botryocyrtis serpentis_, Ehrenberg.

_Botryocyrtis serpentis_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 287, Taf. x. fig. 21.

Cephalis quadrilobate; the odd frontal and the two paired buccal lobes subspherical, about half as large as the odd occipital lobe. Thorax inflated, about as long as the cephalis and half as long as the ovate abdomen. Mouth of the latter constricted, of half the breadth.

_Dimensions._--Length of the shell 0.12, breadth 0.06.

_Habitat._--Indian Ocean (Zanzibar), depth 2200 fathoms, Pullen.

{1121}2. _Botryocyrtis theocampe_, n. sp. (Pl. 96, fig. 19).

Cephalis quadrilobate; the odd frontal and the two paired buccal lobes hemispherical, about half as large as the helmet-shaped occipital lobe. Thorax cylindrical, of equal length and breadth, one and a half times as broad as the cephalis and as the cylindrical abdomen. Pores rather large, irregular, roundish.

_Dimensions._--Length of the shell 0.12, breadth 0.06.

_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.

3. _Botryocyrtis cerebellum_, n. sp. (Pl. 96, fig. 18).

Cephalis quinquelobate; the odd frontal and the two paired buccal lobes ovate, about half as large as the two helmet-shaped paired occipital lobes (?). Thorax campanulate, twice as broad and long as the cephalis and as the truncate cylindrical abdomen.

_Dimensions._--Length of the shell 0.12, breadth 0.08.

_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.

4. _Botryocyrtis quinaria_, Ehrenberg.

_Botryocyrtis quinaria_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 287, Taf. x. fig. 16.

Cephalis quinquelobate; the odd occipital lobe ovate, twice as large as each of the other four subspherical lobes, the two anterior (or frontal) of which are somewhat smaller than the two posterior (or buccal). Thorax campanulate, somewhat larger than the truncate abdomen. Pores rather large, irregular.

_Dimensions._--Length of the shell 0.09, breadth 0.05.

_Habitat._--Indian Ocean (Zanzibar and Madagascar), surface.

Genus 493. _Pylobotrys_,[110] Haeckel, 1881, Prodromus, p. 440.

_Definition._--#Pylobotryida# with tubes on the cephalis, and with the mouth of the abdomen open.

The genus _Pylobotrys_ differs from the closely allied _Acrobotrys_, its ancestral form, in the development of an abdomen or a third shell-joint, the basal mouth of which remains open.

1. _Pylobotrys putealis_, n. sp. (Pl. 96, fig. 21).

Cephalis multilobate, with a single curved and descending tube on the base of its anterior part (sternal tube). Occipital half of the cephalis divided into three large odd lobes (the largest {1122}the apical); facial half divided into three to five lobes, an odd frontal and one or two lateral pairs of small buccal lobes. Thorax truncate conical, about as large as the cephalis and larger than the truncate abdomen. Pores regular circular.

_Dimensions._--Length of the shell 0.12, breadth 0.08.

_Habitat._--Tropical Atlantic Station 347, depth 2250 fathoms.

2. _Pylobotrys fontinalis_, n. sp. (Pl. 96, fig. 20).

Cephalis trilobate, with three ovate lobes in the sagittal plane, of nearly equal size, and two divergent cylindrical tubes conical at the base. An ascending apical tube on the apex of the occipital lobe and a descending sternal tube on the base of the frontal lobe. The middle lobe between the former distinctly exhibits in the apical view (fig. 20) the collar septum with the four cortinar pores. Thorax campanulate, larger than the cephalis and the truncate abdomen.

_Dimensions._--Length of the shell 0.11, breadth 0.06.

_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.

3. _Pylobotrys cerebralis_, n. sp. (Pl. 96, fig. 22).

Cephalis multilobate, with four divergent cylindrical tubes, which are cylindrical, obliquely truncate at the mouth, and correspond in position to the four typical spines of _Cortina_; an ascending apical tube and three descending basal tubes (an odd caudal and two paired pectoral). The helmet-shaped occipital lobe is about as large as the frontal half of the cephalis, which is divided into three pairs of smaller pyriform lobes. Thorax subspherical, about as large as the cephalis and half as large as the inflated abdomen. Pores very scarce and small.

_Dimensions._--Length of the shell 0.15, breadth 0.08.

_Habitat._--Indian Ocean, Cocos Islands, Rabbe, surface.

Genus 494. _Botryocampe_,[111] Ehrenberg, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 829.

_Definition._--#Pylobotryida# without tubes on the cephalis, and with the mouth of the abdomen closed.

The genus _Botryocampe_ may be derived from _Botryocyrtis_ by development of a basal lattice-plate, closing the terminal mouth of the abdomen. It is at the same time closely allied to the Tricyrtid _Theocapsa_, and may be perhaps derived from this by lobation of the cephalis.

{1123}1. _Botryocampe inflata_, Ehrenberg.

_Botryocampe inflata_, Ehrenberg, 1861, Monatsber. d. k. Akad. d. Wiss.
Berlin, p. 296; Abhandl. d. k. Akad. d. Wiss. Berlin, 1872, p. 285,
Taf. ii. fig. 4.

_Botryocampe inflata_, Haeckel, 1862, Monogr. d. Radiol., p. 345.

_Lithobotrys inflata_, Bailey, 1856, Amer. Journ. Sci. and Arts, vol.
xxii. p. 1, pl. i. fig. 15.

Cephalis trilobate, inflated, of about the same breadth and length as the tun-shaped thorax and the hemispherical abdomen. Frontal lobes of the cephalis ovate, a little smaller than the ovate odd occipital lobe. Pores numerous and small.

_Dimensions._--Length of the shell 0.05 to 0.08, breadth 0.02 to 0.04.

_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Pacific, Stations 267 to 274, 241, 354, &c., surface, and in various depths.

2. _Botryocampe theocapsa_, n. sp.

Cephalis trilobate, half as long as the campanulate thorax, and one-third as long as the ovate abdomen. Frontal lobes subspherical, scarcely half as long as the helmet-shaped occipital lobe. Pores very small and scarce.

_Dimensions._--Length of the shell 0.12, breadth 0.04.

_Habitat._--South Atlantic, Station 335, depth 1425 fathoms.

3. _Botryocampe galea_, Haeckel.

_Lithobotrys galea_, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 83.

_Lithocorythium galea_, Ehrenberg, 1854, Mikrogeol., Taf. xxii. fig. 29,
a, b.

_Lithocorythium galea_, Haeckel, 1862, Monogr. d. Radiol., p. 330.

Cephalis quinquelobate, about as large as the ovate thorax, and twice as large as the hemispherical abdomen (which is identical with the "crista obtusa finis anterioris" of Ehrenberg). Occipital lobe helmet-shaped, about twice as long as the two pairs of lateral lobes (the superior frontal and the inferior buccal lobes).

_Dimensions._--Length of the shell 0.08, breadth 0.04.

_Habitat._--Fossil in Barbados.

4. _Botryocampe rotalia_, n. sp. (Pl. 96, fig. 23).

Cephalis quinquelobate, half as large as the campanulate thorax and the subspherical abdomen. Occipital lobe ovate, one and a half times as long as the two ovate frontal lobes, and three times as long as the two subspherical buccal lobes. Collar septum with six distinct cortinar pores (two anterior jugular, two middle cardinal and two posterior cervical, fig. 23).

_Dimensions._--Length of the shell 0.1, breadth 0.06.

_Habitat._--South Pacific, Station 295, depth 1500 fathoms.

{1124}5. _Botryocampe camerata_, n. sp. (Pl. 96, fig. 24).

Cephalis multilobate, about as long and half as broad as the irregularly campanulate thorax, which is half as long as the subspherical large abdomen. Occipital lobe of the cephalis helmet-shaped, larger than its uviform frontal part, which is divided into six to eight small subspherical lobes. In the interior of the thorax and abdomen irregularly branched rods are visible, which divide their inner space into compartments or incomplete chambers. Pores large, regular, circular, hexagonally framed.

_Dimensions._--Length of the shell 0.15, breadth 0.09.

_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.

Genus 495. _Phormobotrys_,[112] Haeckel, 1881, Prodromus, p. 440.

_Definition._--#Pylobotryida# with tubes on the cephalis, and with the mouth of the abdomen closed.

The genus _Phormobotrys_ differs from the similar and closely allied _Pylobotrys_ in the development of a basal lattice-plate closing the terminal mouth of the thorax, and corresponds therefore to _Lithobotrys_ among the Lithobotryida. As in the latter and in _Cannobotrys_, &c., so here in _Phormobotrys_, different subgenera may be distinguished, according to the different number and disposition of the radial tubes which become developed from the lobate cephalis.

1. _Phormobotrys trithalamia_, n. sp. (Pl. 96, fig. 26).

Cephalis trilobate, with a single apical tube, which is only one-third as long, spindle-shaped, pointed, with frontal opening. Frontal lobes ovate, two-thirds as long as the helmet-shaped occipital lobe. Internal frontal septum of the cephalis with four large pores. Thorax cylindrical, twice as long as the hemispherical abdomen. Pores small and numerous, irregular, roundish.

_Dimensions._--Length of the shell 0.16, breadth 0.05.

_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.

2. _Phormobotrys pentathalamia_, n. sp. (Pl. 96, fig. 27).

Cephalis quinquelobate, with a single conical apical tube of the same length, which has an obliquely truncate frontal opening. Odd frontal and paired buccal lobes smaller than the sternal and the occipital lobe. Internal frontal septum with six large pores. Thorax inflated, a little larger than the subspherical abdomen. Pores subregular, circular.

_Dimensions._--Length of the shell 0.15, breadth 0.08.

_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.

{1125}3. _Phormobotrys hexathalamia_, Haeckel.

_Botryocampe hexathalamia_, Haeckel, 1862, Monogr. d. Radiol., p. 344,
Taf. xii. fig. 10.

Cephalis sexlobate, with a single apical horn, which is solid, vertical, cylindrical, pointed, only one-third as long. Frontal lobes subcylindrical, nearly as long as the kidney-shaped occipital lobe, three to four times as long as the small buccal lobes and the odd sternal lobe. Thorax tun-shaped, smaller than the cephalis, larger than the hemispherical abdomen. Pores numerous, subregular, circular.

_Dimensions._--Length of the shell 0.13 to 0.15, breadth 0.05 to 0.06.

_Habitat._--Mediterranean, Messina, surface.

4. _Phormobotrys cannothalamia_, n. sp. (Pl. 96, fig. 25).

Cephalis trilobate, of about the same breadth and length as the campanulate thorax, which is three times as long as the flat cap-shaped abdomen. The middle (or central) lobe of the cephalis is simple, nearly cubical, and smaller than the ovate occipital and frontal lobe. The two latter are prolonged into two slender cylindrical divergent tubes. Pores small and very numerous.

_Dimensions._--Length of the shell 0.1, breadth 0.05.

_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.

5. _Phormobotrys polythalamia_, n. sp.

Cephalis multilobate, of the same length and breadth as the subspherical thorax, and half as long as the ovate abdomen. Occipital lobe helmet-shaped, about as large as the frontal half of the cephalis, which is divided into six to eight lobes (two odd and two or three pairs of lateral lobes). Four cylindrical tubes corresponding to the four typical spines of _Cortina_, an ascending apical and three descending basal tubes (a posterior caudal and two anterior pectoral).

_Dimensions._--Length of the shell 0.14, breadth 0.08.

_Habitat._--South Pacific, Station 298, depth 2225 fathoms.

{1126}----

Suborder III. CYRTOIDEA, Haeckel, 1862.

_Cyrtida_, Haeckel, 1862, Monogr. d. Radiol., pp. 272, 280.
_Cyrtoidea_ vel _Cyrtida_, Haeckel, 1881, Prodromus, pp. 425-439.
_Polycystina solitaria_, Ehrenberg, 1847, Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, pp. 53, 54.
_Monodictya nassellaria_, Ehrenberg, 1875, Abhandl. d. k. preuss. Akad.
d. Wiss. Berlin, pp. 156, 157.

_Definition._--NASSELLARIA with a complete lattice-shell, exhibiting a simple or reduced cephalis, which is neither bilocular nor lobate, without sagittal constriction.

The order #Cyrtoidea#, described by me in 1862 as the family Cyrtida, is by far the largest of all the main groups of Radiolaria, and remarkable from the extraordinary variety of forms and the number of species. In the following system more than eleven hundred species are described, comprising about one-fourth of the number of species in the whole class of Radiolaria. This astonishing variety, however, is not effected by development of a large number of different types, but by an extraordinary variability within certain restricted boundaries, similar to what is seen among insects and birds. The number of genera, therefore, is comparatively small, and they may all be disposed into four families only, which in my Monograph (1862, p. 280) were distinguished as Monocyrtida, Dicyrtida, Tricyrtida and Stichocyrtida. If we divide these four groups in the following pages into twelve families and twenty-four subfamilies, we are guided by practical considerations only, hoping thereby to give a better survey of the difficult labyrinth of Cyrtoidean morphology.

The #Cyrtoidea# are characterised by this wonderful richness of specific forms not only in the present seas, but also for millions of years in the former ages of our globe. The majority of all the fossil Radiolaria which are now known belong to this group, and many species of it are so common that great rocks are formed by their union. The fact was first observed by Ehrenberg, who in his first system of _Polycystina_ (1847, _loc. cit._, p. 54) enumerated forty-four genera and two hundred and eighty-two species; the #Cyrtoidea#, his Polycystina solitaria, form the preponderant majority of the whole class, viz., twenty-five genera and one hundred and ninety-three species.