Chapter XIV: Front Matter (14)

The majority of the Crustacea are hatched from the egg in a form
differing more or less from that of the adult, and pass through a
series of free-swimming larval stages. There are many cases, however,
in which the metamorphosis is suppressed, and the newly-hatched young
resemble the parent in general structure. The relative size of the
eggs and the amount of nutritive yolk which they contain are generally
much greater in those forms which have a direct development.

The details of the early embryonic stages vary considerably within the
limits of the class. They are of interest, however, rather from the
point of view of general embryology than from that of the special
student of the Crustacea, and cannot be fully dealt with here.

Segmentation is usually of the superficial or centrolecithal type. The
hypoblast is formed either by a definite invagination or by the
immigration of isolated cells, known as vitellophags, which wander
through the yolk and later become associated into a definite
mesenteron, or by some combination of these two methods. The
blastopore generally occupies a position corresponding to the
posterior end of the body. The mesoblast of the cephalic (naupliar)
region probably arises in connexion with the lips of the blastopore
and consists of loosely-connected cells or mesenchyme. In the region
of the trunk, in many cases, paired mesoblastic bands are formed,
growing in length by the division of teloblastic cells at the
posterior end, and becoming segmented into somites. The existence of
true coelom-sacs is somewhat doubtful. The rudiments of the first
three pairs of appendages commonly appear simultaneously, and, even in
forms with embryonic development, they show differences in their mode
of appearance from the succeeding somites. Further, a definite
cuticular membrane is frequently formed and shed at this stage, which
corresponds to the nauplius-stage of larval development.

The larval metamorphoses of the Crustacea have attracted much
attention, and have been the subject of much discussion in view of
their bearing on the phylogenetic history of the group. In those
Crustacea in which the series of larval stages is most complete, the
starting-point is the form already mentioned under the name of
_nauplius_. The typical nauplius (fig. 12) has an oval unsegmented
body and three pairs of limbs corresponding to the antennules,
antennae and mandibles of the adult. The antennules are uniramous, the
others biramous, and all three pairs are used in swimming. The
antennae have a spiniform or hooked masticatory process at the base,
and share with the mandibles, which have a similar process, the
function of seizing and masticating the food. The mouth is overhung by
a large labrum or upper lip, and the integument of the dorsal surface
of the body forms a more or less definite dorsal shield. The paired
eyes are, as yet, wanting, but the unpaired eye is large and
conspicuous. A pair of frontal papillae or filaments, probably
sensory, are commonly present.

A nauplius larva differing only in details from the typical form just
described is found in the majority of the Phyllopoda, Copepoda and
Cirripedia, and in a more modified form, in some Ostracoda. Among the
Malacostraca the nauplius is less commonly found, but it occurs in the
_Euphausiidae_ among the Schizopoda and in a few of the more primitive
Decapoda (_Penaeidea_) (fig. 12). In most of the Crustacea which hatch
at a later stage there is, as already mentioned, more or less clear
evidence of an embryonic nauplius stage. It seems certain, therefore,
that the possession of a nauplius larva must be regarded as a very
primitive character of the Crustacean stock.

As development proceeds, the body of the nauplius elongates, and
indications of segmentation begin to appear in its posterior part. At
successive moults the somites increase in number, new somites being
added behind those already differentiated, from a formative zone in
front of the telsonic region. Very commonly the posterior end of the
body becomes forked, two processes growing out at the sides of the
anus and often persisting in the adult as the "caudal furca." The
appendages posterior to the mandibles appear as buds on the ventral
surface of the somites, and in the most primitive cases they become
differentiated, like the somites which bear them, in regular order
from before backwards. The limb-buds early become bilobed and grow out
into typical biramous appendages which gradually assume the characters
found in the adult. With the elongation of the body, the dorsal shield
begins to project posteriorly as a shell-fold, which may increase in
size to envelop more or less of the body or may disappear altogether.
The rudiments of the paired eyes appear under the integument at the
sides of the head, but only become pedunculated at a comparatively
late stage.

The course of development here outlined, in which the nauplius
gradually passes into the adult form by the successive addition of
somites and appendages in regular order, agrees so well with the
process observed in the development of the typical Annelida that we
must regard it as being the most primitive method. It is most closely
followed by the Phyllopods such as _Apus_ or _Branchipus_, and by some
Copepoda.

A, Nauplius. e, Eye.
B, _Cypris_-larva with a bivalve shell and just before becoming
attached (represented feet upwards for comparison with E, where it
is attached).
C, After becoming attached, side views.
D, Later stage, viewed from above.
E, Side view, later stage and with cirri extended.

The dots indicate the actual size.]

r, Rostral spine.
s, Dorsal spine.
m, Maxillipeds.
t, Buds of thoracic feet.
a, Abdomen.]

In most Crustacea, however, this primitive scheme is more or less
modified. The earlier stages may be suppressed or passed through
within the egg (or within the maternal brood-chamber), so that the
larva, on hatching, has reached a stage more advanced than the
nauplius. Further, the gradual appearance and differentiation of the
successive somites and appendages may be accelerated, so that
comparatively great advances take place at a single moult. In the
Cirripedia, for example, the latest nauplius stage (fig. 13, A) gives
rise directly to the so-called _Cypris_-larva (fig. 13, B), differing
widely from the nauplius in form, and possessing all the appendages of
the adult. Another very common modification of the primitive method of
development is found in the accelerated appearance of certain somites
or appendages, disturbing the regular order of development. This
modification is especially found in the Malacostraca. Even in those
which have most fully retained the primitive order of development, as
in the _Penaeidea_ and _Euphausiidae_, the last pair of abdominal
appendages make their appearance in advance of those immediately in
front of them. The same process, carried further, leads to the very
peculiar larva known as the _Zoea_, in the typical form of which,
found in the Brachyura (fig. 14), the posterior five or six thoracic
somites have their development greatly retarded, and are still
represented by a short unsegmented region of the body at a time when
the abdominal somites are fully formed and even carry appendages. The
_Zoea_ was formerly regarded as a recapitulation of an ancestral form,
but there can be no doubt that its peculiarities are the result of
secondary modification. It is most typically developed in the most
specialized Decapoda, the Brachyura, while the more primitive groups
of Malacostraca, the _Euphausiidae_, _Penaeidea_ and Stomatopoda,
retain the primitive order of appearance of the somites, and, for the
most part, of the limbs. At the same time, the tendency to a
retardation in the development of the posterior thoracic somites is
very general in Malacostracan larvae, and may perhaps be correlated
with the fact that in the primitive Phyllocarida the whole thoracic
region is very short and the limbs closely crowded together.

(Fritz Muller.)]

Besides the nauplius and the zoea there are many other types of
Crustacean larvae, distinguished by special names, though, as their
occurrence is restricted within the limits of the smaller systematic
groups, they are of less general interest. We need only mention the
_Mysis_-stage (better termed Schizopod-stage) found in many Macrura
(as, for example, the lobster), which differs from the adult in having
large natatory exopodites on the thoracic legs.

Most of the larval forms swim freely at the surface of the sea, and
many show special adaptations to this habit of life. As in many other
"pelagic" organisms, spines and processes from the surface of the body
are often developed, which are probably less important as defensive
organs than as aids to flotation. This is well seen in the nauplius of
many Cirripedia (fig. 15) and in nearly all zoeae. Perhaps the most
striking example is the zoea-like larva of the _Sergestidae_, known as
_Elaphocaris_, which has an extraordinary armature of ramified spines.
The same purpose is probably served by the extreme flattening of the
body in the membranous _Phyllosoma_-larva of the rock-lobsters and
their allies (Loricata).

_Past History._

Although fossil remains of Crustacea are abundant, from the most ancient fossiliferous rocks down to the most recent, their study has hitherto contributed little to a precise knowledge of the phylogenetic history of the class. This is partly due to the fact that many important forms must have escaped fossilization altogether owing to their small size and delicate structure, while very many of those actually preserved are known only from the carapace or shell, the limbs being absent or represented only by indecipherable fragments. Further, many important groups were already differentiated when the geological record began. The Phyllopoda, Ostracoda and Cirripedia (Thyrostraca) are represented in Cambrian or Silurian rocks by forms which seem to have resembled closely those now existing, so that palaeontology can have little light to throw on the mode of origin of these groups. With the Malacostraca the case is little better. There is considerable reason for believing that the _Ceratiocaridae_, which are found from the Cambrian onwards, were allied to the existing _Nebalia_, and may possibly include the forerunners of the true Malacostraca, but nothing is definitely known of their appendages. In Palaeozoic formations, from the Upper Devonian onwards, numbers of shrimp-like forms are found which have been referred to the Schizopoda and the Decapoda, but here again the scanty information which may be gleaned as to the structure of the limbs rarely permits of definite conclusions as to their affinities. The recent discovery in the Tasmanian "schizopod" _Anaspides_, of what is believed to be a living representative of the Carboniferous and Permian _Syncarida_, has, however, afforded a clue to the affinities of some of these problematical forms.

True Decapods are first met with in Mesozoic rocks, the first to appear being the _Penaeidea_, a primitive group comprising the _Penaeidae_ and _Sergestidae_, which occur in the Jurassic and perhaps in the Trias. Some of the earliest are referred to the existing genus _Penaeus_. The Stenopidea, another primitive group, differing from the Penaeidea in the character of the gills, appear in the Trias and Jurassic. The Caridea or true prawns and shrimps appear later, in the Upper Jurassic, some of them presenting primitive characteristics in the retention of swimming exopodites on the walking-legs. The Eryonidea (fig. 16, 3), a group related to the Loricata but of a more generalized type, are specially interesting since the few existing deep-sea forms appear to be only surviving remnants of what was, in the Mesozoic period, a dominant group. The Mesozoic _Glyphaeidae_ have been supposed to stand in the direct line of descent of the modern rock-lobsters and their allies (Loricata). Some of the Loricata have persisted with little change from the Cretaceous period to the present day.

1, _Dromilites Lamarckii_, Desm.; London Clay, Sheppey.
2, _Palaeocorystes Stokesii_, Gault; Folkestone.
3, _Eryon arctiformis_, Schl.; Lithographic stone, Solenhofen.
4, _Mecocheirus longimanus_, Schl.; Lithographic stone, Solenhofen.
5, _Cypridea tuberculata_, Sby.; (Ostracoda); Weald, Sussex.
6, _Loricula pulchella_, Sby (Cirripedia); L. Chalk, Sussex.]

The Anomura are hardly known as fossils. The Brachyura, on the other hand, are well represented (fig 16, 1, 2). The earliest forms, from the Lower Oolite and later, belonging chiefly to the extinct family _Prosoponidae_, have been shown to have close relations with the most generalized of existing Brachyura, the deep-sea _Homolodromiidae_, and to link the Brachyura to the Homarine (lobster-like) Macrura.

A few Isopoda are known from Secondary rocks, but their systematic position is doubtful and they throw no light on the evolution of the group. The Amphipoda are not definitely known to occur till Tertiary times. Stomatopoda of a very modern-looking type, and even their larvae, occur in Jurassic rocks.

In the dearth of trustworthy evidence as to the actual forerunners of existing Crustacea, we are compelled to rely wholly on the data afforded by comparative anatomy and embryology in attempting to reconstruct the probable phylogeny of the class. It is unnecessary to insist on the purely speculative character of the conclusions to be reached in this way, so long as they cannot be checked by the results of palaeontology, but, when this is recognized, such speculation is not only legitimate but necessary as a basis on which to build a natural classification.

The first attempts to reconstruct the genealogical history of the Crustacea started from the assumption that the "theory of recapitulation" could be applied to their larval history. The various larval forms, especially the nauplius and zoea, were supposed to reproduce, more or less closely, the actual structure of ancestral types. So far as the zoea was concerned, this assumption was soon shown to be erroneous, and the secondary nature of this type of larva is now generally admitted. As regards the nauplius, however, the constancy of its general character in the most widely diverse groups of Crustacea strongly suggests that it is a very ancient type, and the view has been advocated that the Crustacea must have arisen from an unsegmented nauplius-like ancestor.

The objections to this view, however, are considerable. The resemblances between the Crustacea and the Annelid worms, in such characters as the structure of the nervous system and the mode of growth of the somites, can hardly be ignored. Several structures which must be attributed, to the common stock of the Crustacea, such as the paired eyes and the shell-fold, are not present in the nauplius. The opinion now most generally held is that the primitive Crustacean type is most nearly approached by certain Phyllopods such as _Apus_. The large number and the uniformity of the trunk somites and their appendages, and the structure of the nervous system and of the heart in _Apus_, are Annelidan characters which can hardly be without significance. It is probable also, as already mentioned, that the leaf-like appendages of the Phyllopoda are of a primitive type, and attempts have been made to refer their structure to that of the Annelid parapodium. In many respects, however, the Phyllopoda, and especially _Apus_, have diverged considerably from the primitive Crustacean type. All the cephalic appendages are much reduced, the mandibles have no palps, and the maxillulae are vestigial. In these respects some of the Copepoda have retained characters which we must regard as much more primitive. In those Copepods in which the palps of the mandibles as well as the antennae are biramous and natatory, the first three pairs of appendages retain throughout life, with little modification, the shape and function which they have in the nauplius stage, and must, in all likelihood, be regarded as approximating to those of the primitive Crustacea. In other respects, however, such as the absence of paired eyes and of a shell-fold, as well as in the characters of the post-oral limbs, the Copepoda are undoubtedly specialized.

In order to reconstruct the hypothetical ancestral Crustacean, therefore, it is necessary to combine the characters of several of the existing groups. It may be supposed to have approximated, in general form, to _Apus_, with an elongated body composed of numerous similar somites and terminating in a caudal furca; with the post-oral appendages all similar and all bearing gnathobasic processes; and with a carapace originating as a shell-fold from the maxillary somite. The eyes were probably stalked, the antennae and mandibles biramous and natatory, and both armed with masticatory processes. It is likely that the trunk-limbs were also biramous, with additional endites and exites. Whether any of the obscure fossils generally referred to the Phyllopoda or Phyllocarida may have approximated to this hypothetical form it is impossible to say. It is to be noted, however, that the Trilobita, which, according to the classification here adopted, are dealt with under Arachnida, are not very far removed, except in such characters as the absence of a shell-fold and of eye-stalks, from the primitive Crustacean here sketched.

On this view, the nauplius, while no longer regarded as reproducing an ancestral type, does not altogether lose its phylogenetic significance. It is an ancestral _larval_ form, corresponding perhaps to the stages immediately succeeding the trochophore in the development of Annelids, but with some of the later-acquired Crustacean characters superposed upon it. While little importance is to be given to such characters as the unsegmented body, the small number of limbs and the absence of a shell-fold and of paired eyes, it has, on the other hand, preserved archaic features in the form of the limbs and the masticatory function of the antenna.

The probable course of evolution of the different groups of Crustacea from this hypothetical ancestral form can only be touched on here. The Phyllopoda must have branched off very early and from them to the Cladocera the way is clear. The Ostracoda might have been derived from the same stock were it not that they retain the mandibular palp which all the Phyllopods have lost. The Copepoda must have separated themselves very early, though perhaps some of their characters may be persistently larval rather than phylogenetically primitive. The Cirripedia are so specialized both as larvae and as adults that it is hard to say in what direction their origin is to be sought.

For the Malacostraca, it is generally admitted that the Leptostraca (_Nebalia_, &c.) provide a connecting-link with the base of the Phyllopod stem. Nearest to them come the Schizopoda, a primitive group from which two lines of descent can be traced, the one leading from the Mysidacea (_Mysidae_ + _Lophogastridae_) to the Cumacea and the sessile-eyed groups Isopoda and Amphipoda, the other from the Euphausiacea (_Euphausiidae_) to the Decapoda.

_Classification._

The modern classification of Crustacea may be said to have been founded by P. A. Latreille, who, in the beginning of the 19th century, divided the class into Entomostraca and Malacostraca. The latter division, characterized by the possession of 19 somites and pairs of appendages (apart from the eyes), by the division of the appendages into two tagmata corresponding to cephalothorax and abdomen, and by the constancy in position of the generative apertures, differing in the two sexes, is unquestionably a natural group. The Entomostraca, however, are certainly a heterogeneous assemblage, defined only by negative characters, and the name is retained only for the sake of convenience, just as it is often useful to speak of a still more heterogeneous and unnatural assemblage of animals as Invertebrata. The barnacles and their allies, forming the group Cirripedia or Thyrostraca, sometimes treated as a separate sub-class, are distinguished by being sessile in the adult state, the larval antennules serving as organs of attachment, and the antennae being lost. An account of them will be found in the article THYROSTRACA. The remaining groups are dealt with under the headings ENTOMOSTRACA and MALACOSTRACA, the annectent group Leptostraca being included in the former.

It may be useful to give here a synopsis of the classification adopted in this encyclopaedia, noting that, for convenience of treatment, it has been thought necessary to adopt a grouping not always expressive of the most recent views of affinity.

Class _Crustacea_.
Sub-class _Entomostraca_.
Order _Branchiopoda_.
Sub-orders _Phyllopoda_.
_Cladocera_.
_Branchiura_.
Orders _Ostracoda_.
_Copepoda_.
Sub-classses _Thyrostraca_ (_Cirripedia_).
_Leptostraca_.
_Malacostraca_.
Order _Decapoda_.
Sub-orders _Brachyura_.
_Macrura_.
Orders _Schizopoda_ (including _Anaspides_).
_Stomatopoda_.
_Sympoda_ (Cumacea).
_Isopoda_ (including _Tanaidacea_).
_Amphipoda_.

(W. T. Ca.)

CRUSTUMERIUM, an ancient town of Latium, on the edge of the Sabine territory, near the headwaters of the Allia, not far from the Tiber. It appears several times in the early history of Rome, but was conquered in 500 B.C. according to Livy ii. 19, the _tribus Crustumina_ [or _Clustumina_] being formed in 471 B.C. Pliny mentions it among the lost cities of Latium, but the name clung to the district, the fertility of which remained famous. No remains of it exist, and its exact site is uncertain.

See T. Ashby in _Papers of the British School at Rome_, iii. 50.

CRUVEILHIER, JEAN (1791-1874), French anatomist, was born at Limoges in 1791, and was educated at the university of Paris, where in 1825 he became professor of anatomy. In 1836 he became the first occupant of the recently founded chair of pathological anatomy. He died at Jussac in 1874. His chief works are _Anatomie descriptive_ (1834-1836); _Anatomie pathologique du corps humain_ (1829-1842), with many coloured plates; _Traite d'anatomie pathologique generale_ (1849-1864); _Anatomie du systeme nerveux de l'homme_ (1845); _Traite d'anatomie descriptive_ (1851).

CRUZ E SILVA, ANTONIO DINIZ DA (1731-1799), Portuguese heroic-comic poet, was the son of a Lisbon carpenter who emigrated to Brazil shortly before the poet's birth, leaving his wife to support and educate her young family by the earnings of her needle. Diniz studied Latin and philosophy with the Oratorians, and in 1747 matriculated at Coimbra University, where he wrote his first versus about 1750. In 1753 he took his degree in law, and returning to the capital, devoted much of the next six years to literary work. In 1756 he became one of the founders and drew up the statues of the _Arcadia Lusitana_, a literary society whose aims were the instruction of its members, the cultivation of the art of poetry, and the restoration of good taste. The fault was not his if these ends were not attained, for, taking contemporary French authors as his models, he contributed much, both in prose and verse, to its proceedings, until he left in February 1760 to take up the position of _juiz de fora_ at Castello de Vide. On returning to Lisbon for a short visit, he found the _Arcadia_ a prey to the internal dissensions that caused its dissolution in 1774, but succeeded in composing them and in 1764 he went to Elvas to act as auditor of one of the regiments stationed there. During a ten years' residence, his wide reading and witty conversation gained him the friendship of the governor of that fortress and the admiration of a circle comprising all that was cultivated in Elvas. As in most cathedral and garrison towns, the clerical and military elements dominated society, and here were mutually antagonistic, because of the enmity between their respective leaders, the bishop and the governor. Moreover, Elvas, being a remote provincial centre, abounded in curious and grotesque types. Diniz, who was a keen observer, noted these, and, treasuring them in his memory, reproduced them, with their vanities, intrigues and ignorance, in his masterpiece, _Hyssope_. In 1768 a quarrel arose between the bishop, a proud, pretentious prelate, and the dean, as to the right of the former to receive holy water from the latter at a private side door of the cathedral, instead of at the principal entrance. The matter being one of principle, neither party would yield what he considered his rights, and it led to a lawsuit, and divided the town into two sections, which eagerly debated the arguments on both sides and enjoyed the ridiculous incidents which accompanied the dispute. Ultimately the dean died, and was succeeded by his nephew, who appealed to the crown with success and the bishop lost his pretension. The _Hyssope_ arose out of and deals with this affair. It was dictated in seventeen days, in the years 1770-1772, and, in its final redaction, consists of eight cantos of blank verse. The pressure of absolutism left open only one form of expression, satire, and in this poem Diniz produced an original work which ridicules the clergy and the prevailing Gallomania, and contains episodes full of humour. It has been compared with Boileau's _Lutrin_, because both are founded on a petty ecclesiastical quarrel, but here the resemblance ends, and the poem of Diniz is the superior in everything except matrification.

Returning to Lisbon in 1774, Diniz endeavoured once more to resuscitate the _Arcadia_, but his long absence had withdrawn its chief support, its most talented members Garcao (q.v.) and Quita were no more, and he only assisted at its demise. In April 1776 he was appointed _disembargador_ of the court of Relacao in Rio de Janeiro and given the habit of Aviz. He lived in Brazil, devouting his leisure to a study of its natural history and mineralogy, until 1789, when he went back to Lisbon to take up the post of _disembargador_ of the Relacao of Oporto; in July 1790 he was promoted, and became _disembargador_ of the Casa da Supplicacao. In this year he was sent again to Brazil to assist in trying the leaders of the Republican conspiracy in Minas, in which Gonzaga (q.v.) and the other men of letters were involved, and in December 1792 he became chancellor of the Relacao in Rio. Six years later he was named councillor of the _Conselho Ultramarino_, but did not live to return home, dying in Rio on the 5th of October 1799.

Diniz possessed a poetic temperament, but his love of imitating the classics, whose spirit he failed to understand, fettered his muse, and he seems never to have perceived that mythological comparisons and pastoral allegories were poor substitutes for the expression of natural feeling. The conventionalism of his art prejudiced its sincerity, and, inwardly cherishing the belief that poetry was unworthy of the dignity of a judge, he never gave his real talents a chance to display themselves. His Anacreontic odes, dithyrambs and idylls earned the admiration of contemporaries, but his Pindaric odes lack fire, his sonnets are weak, and his idylls have neither the truth nor the simplicity of Quita's work. As a rule Diniz's versification is weak and his verses lack harmony, though the diction is beyond cavil.

His poems were published in 6 vols. (Lisbon, 1807-1817). The best
edition of _Hyssope_, to which Diniz owes his lasting fame, is that of
J. R. Coelho (Lisbon, 1879), with an exhaustive introductory study on
his life and writings. A French prose version of the poem by
Boissonade has gone through two editions (Paris, 1828 and 1867), and
English translations of selections have been printed in the _Foreign
Quarterly Review_, and in the _Manchester Quarterly_ (April 1896).

See also Dr Theophilo Braga, _A. Arcadia Lusitana_ (Oporto, 1899).
(E. Pr.)

CRYOLITE, a mineral discovered in Greenland by the Danes in 1794, and found to be a compound of fluorine, sodium and aluminium. From its general appearance, and from the fact that it melts readily, even in a candle-flame, it was regarded by the Eskimos as a peculiar kind of ice; from this fact it acquired the name of cryolite (from Gr. [Greek: kryos], frost, and [Greek: lithos], stone). Cryolite occurs in colourless or snow-white cleavable masses, often tinted brown or red with iron oxide, and occasionally passing into a black variety. It is usually translucent, becoming nearly transparent on immersion in water. The mineral cleaves in three rectangular directions, and the crystals occasionally found in the crevices have a cubic habit, but it has been proved, after much discussion, that they belong to the anorthic system. The hardness is 2.5, and the specific gravity 3. Cryolite has the formula Na3AlF6, or 3NaF.AlF3, corresponding to fluorine 54.4, sodium 32.8, and aluminium 12.8%. It colours a flame yellow, through the presence of sodium, and when heated with sulphuric acid it evolves hydrofluoric acid.

Cryolite occurs almost exclusively at Ivigtut (sometimes written Evigtok) on the Arksut Fjord in S.W. Greenland. There it forms a large deposit, in a granitic vein running through gneiss, and is accompanied by quartz, siderite, galena, blende, chalcopyrite, &c. It is also associated with a group of kindred minerals, some of which are evidently products of alteration of the cryolite, known as pachnolite, thomsenolite, ralstonite, gearksutite, arksutite, &c. Cryolite likewise occurs, though only to a limited extent, at Miyask, in the Ilmen Mountains; at Pike's Peak, Colorado, and in the Yellowstone Park.

Cryolite is a mineral of much economic importance. It has been extensively used as a source of metallic aluminium, and as a flux in smelting the metal. It is largely employed in the manufacture of certain sodium salts, as suggested by Julius Thomsen, of Copenhagen, in 1849; and it has been used for the production of certain kinds of porcelain and glass, remarkable for its toughness, and for enamelled ware.

Although cryolite is known as "ice-stone" (_Eisstein_), it is not to be confused with "ice-spar" (_Eisspath_), which is a vitreous kind of felspar termed "glassy felspar" or rhyacolite. (F. W. R.*)

CRYPT (Lat. _crypta_, from the Gr. [Greek: kryptein], to hide), a vault or subterranean chamber, especially under churches. In classical phraseology "crypta" was employed for any vaulted building, either partially or entirely below the level of the ground. It is used for a sewer (_crypta Suburae_, Juvenal, _Sat._ v. 106); for the "carceres," or vaulted stalls for the horses and chariots in a circus (Sidon. Apoll. _Carm._ xxiii. 319); for the close porticoes or arcades, more fully known as "cryptoporticus," attached by the Romans to their suburban villas for the sake of coolness, and to the theatres as places of exercise or rehearsal for the performers (Plin. _Epist._ ii. 15, v. 6, vii. 21; Sueton. _Calig._ 58; Sidon. Apoll, lib. ii. epist. 2); and for underground receptacles for agricultural produce (Vitruv. vi. 8, Varro, _De re rust._ i. 57). Tunnels, or galleries excavated in the living rock, were also called _cryptae_. Thus the tunnel to the north of Naples, through which the road passes to Puteoli, familiar to tourists as the "Grotto of Posilipo," was originally designated _crypta Neapolitana_ (Seneca, Epist. 57). In early Christian times _crypta_ was appropriately employed for the galleries of a catacomb, or for the catacomb itself. Jerome calls them by this name when describing his visits to them as a schoolboy, and the term is used by Prudentius (see CATACOMBS).

A crypt, as a portion of a church, had its origin in the subterranean chapels known as "confessiones," erected around the tomb of a martyr, or the place of his martyrdom. This is the origin of the spacious crypts, some of which may be called subterranean churches, of the Roman churches of S. Prisca, S. Prassede, S. Martino ai Monti, S. Lorenzo fuori le Mura, and above all of St Peter's--the crypt being thus the germ of the church or basilica subsequently erected above the hallowed spot. When the martyr's tomb was sunk in the surface of the ground, and not placed in a catacomb chapel, the original memorial-shrine would be only partially below the surface, and consequently the part of the church erected over it, which was always that containing the altar, would be elevated some height above the ground, and be approached by flights of steps. This fashion of raising the chancel or altar end of a church on a crypt was widely imitated long after the reason for adopting it ceased, and even where it never existed. The crypt under the altar at the basilica of St Maria Maggiore in Rome is merely imitative, and the same may be said of many of the crypts of the early churches in England. The original Saxon cathedral of Canterbury had a crypt beneath the eastern apse, containing the so-called body of St Dunstan, and other relics, "fabricated," according to Eadmer, "in the likeness of the confessionary of St Peter at Rome" (see BASILICA). St Wilfrid constructed crypts still existing beneath the churches erected by him in the latter part of the 7th century at Hexham and Ripon. These are peculiarly interesting from their similarity in form and arrangement to the catacomb chapels with which Wilfrid must have become familiar during his residence in Rome. The cathedral, begun by Aethelwold and finished by Alphege at Winchester, at the end of the 10th century, had spacious crypts "supporting the holy altar and the venerable relics of the saints" (Wulstan, _Life of St Aethelwold_), and they appear to have been common in the earlier churches in England. The arrangement was adopted by the Norman builders of the 11th and 12th centuries, and though far from universal is found in many of the cathedrals of that date. The object of the construction of these crypts was twofold,--to give the altar sufficient elevation to enable those below to witness the sacred mysteries, and to provide a place of burial for those holy men whose relics were the church's most precious possession. But the crypt was "a foreign fashion," derived, as has been said, from Rome, "which failed to take root in England, and indeed elsewhere barely outlasted the Romanesque period" (_Essays on Cathedrals_, ed. Howson, p. 331).

Of the crypts beneath English Norman cathedrals, that under the choir of Canterbury (q.v.) is by far the largest and most elaborate in its arrangements. It is, in fact, a subterranean church of vast size and considerable altitude. The whole crypt was dedicated to the Virgin Mary, and contained two chapels especially dedicated to her,--the central one beneath the high altar, enclosed with rich Gothic screen-work, and one under the south transept. This latter chapel was appropriated by Queen Elizabeth to the use of the French Huguenot refugees who had settled at Canterbury in the time of Edward VI. There were also in this crypt a large number of altars and chapels of other saints, some of whose hallowed bodies were buried here. At the extreme east end, beneath the Trinity chapel, the body of St Thomas (Becket) was buried the day after his martyrdom, and lay there till his translation, July 7, 1220.

The cathedrals of Winchester, Worcester and Gloucester have crypts of slightly earlier date (they may all be placed between 1080 and 1100), but of similar character, though less elaborate. They all contain piscinas and other evidences of the existence of altars in considerable numbers. They are all apsidal. The most picturesque is that of Worcester, the work of Bishop Wulfstan (1084), which is remarkable for the multiplicity of small pillars supporting its radiating vaults. Instead of having the air of a sepulchral vault like those of Winchester and Gloucester, this crypt is, in Professor Willis's words, "a complex and beautiful temple." Archbishop Roger's crypt at York, belonging to the next century (1154-1181), was filled up with earth when the present choir was built at the end of the 14th century, and its existence forgotten till its disinterment after the fire of 1829. The choir and presbytery at Rochester are supported by an extensive crypt, of which the western portion is Gundulf's work (1076-1107), but the eastern part, which displays slender cylindrical and octagonal shafts, with light vaulting springing from them, is of the same period as the superstructure, the first years of the 13th century. This crypt, and that beneath the Early English Lady chapel at Hereford, are the latest English existing cathedral crypts. That at Hereford was rendered necessary by the fall of the ground, and is an exceptional case. Later than any of these crypts was that of St Paul's, London. This was a really large and magnificent church of Decorated date, with a vaulted roof of rich and intricate character resting on a forest of clustered columns. Part of it served as the parish church of St Faith. A still more exquisite work of the Decorated period is the crypt of St Stephen's chapel at Westminster, than which it is difficult to conceive anything more perfect in design or more elaborate in ornamentation. Having happily escaped the conflagration of the Houses of Parliament in 1834--before which it was degraded to the purpose of the speaker's state dining-room--it has been restored to its former sumptuousness of decoration, and is now one of the most beautiful architectural gems in England.

Of Scottish cathedrals the only one that possesses a crypt is the cathedral of Glasgow, rendered celebrated by Sir Walter Scott in his novel of _Rob Roy_ (ch. xx.). At the supposed date of the tale, and indeed till a comparatively recent period, this crypt was used as a place of worship by one of the three congregations among which the cathedral was partitioned, and was known as "the Laigh or Barony Kirk." It extends beneath the choir transepts and chapter-house; in consequence of the steep declivity on which the cathedral stands it is of unusual height and lightsomeness. It belongs to the 13th century, its style corresponding to Early English, and is simply constructional, the building being adapted to the locality. In architectural beauty it is quite unequalled by any crypt in the United Kingdom, and can hardly anywhere be surpassed. It is an unusually rich example of the style, the clustered piers and groining being exquisite in design and admirable in execution. The bosses of the roof and capitals of the piers are very elaborate, and the doors are much enriched with foliage. "There is a solidity in its architecture, a richness in its vaulting, and a variety of perspective in the spacing of its pillars, which make it one of the most perfect pieces of architecture in these kingdoms" (Fergusson).

In the centre of the main alley stands the mutilated effigy of St Mungo, the patron saint of Glasgow, and at the south-east corner is a well called after the same saint.

Crypts under parish churches are not very uncommon in England, but they are usually small and not characterized by any architectural beauty. A few of the earlier crypts, however, deserve notice. One of the earliest and most remarkable is that of the church of Lastingham near Pickering in Yorkshire, on the site of the monastery founded in 648 by Cedd, bishop of the East Saxons. The existing crypt, though exceedingly rude in structure, is of considerably later date than Bishop Cedd, forming part of the church erected by Abbot Stephen of Whitby in 1080, when he had been driven inland by the incursions of the northern pirates. This crypt is remarkable from its extending under the nave as well as the chancel of the upper church, the plan of which it accurately reproduces, with the exception of the westernmost bay. It forms a nave with side aisles of three bays, and an apsidal chancel, lighted by narrow deeply splayed slits. The roof of quadripartite vaulting is supported by four very dwarf thick cylindrical columns, the capitals of which and of the responds are clumsy imitations of classical work with rude volutes. Still more curious is the crypt beneath the chancel of the church of Repton in Derbyshire. This also consists of a centre and side aisles, divided by three arches on either side. The architectural character, however, is very different from that at Lastingham, and is in some respects almost unique, the piers being slender, and some of them of a singular spiral form, with a bead running in the sunken part of the spiral. Another very extensive and curious Norman crypt is that beneath the chancel of St Peter's-in-the-East at Oxford. This is five bays in length, the quadripartite vaulting being supported by eight low, somewhat slender, cylindrical columns with capitals bearing grotesque animal and human subjects. Its dimensions are 36 by 20 ft. and 10 ft. in height. This crypt has been commonly attributed to Grymboldt in the 9th century; but it is really not very early Norman. Under the church of St Mary-le-Bow in London there is an interesting Norman crypt not very dissimilar in character to that last described. Of a later date is the remarkably fine Early English crypt groined in stone, beneath the chancel of Hythe in Kent, containing a remarkable collection of skulls and bones, the history of which is quite uncertain. There is also a Decorated crypt beneath the chancel at Wimborne minster, and one of the same date beneath the southern chancel aisle at Grantham.

Among the more remarkable French crypts may be mentioned those of the cathedrals of Auxerre, said to date from the original foundation in 1085; of Bayeux, attributed to Odo, bishop of that see, uterine brother of William the Conqueror, where twelve columns with rude capitals support a vaulted roof; of Chartres, running under the choir and its aisles, frequently assigned to Bishop Fulbert in 1029, but more probably coeval with the superstructure; and of Bourges, where the crypt is in the Pointed style, extending beneath the choir. The church of the Holy Trinity attached to Queen Matilda's foundation--the "Abbaye aux Dames" at Caen--has a Norman crypt where the thirty-four pillars are as closely set as those at Worcester. The church of St Eutropius at Saintes has also a crypt of the 11th century, of very large dimensions, which deserves special notice; the capitals of the columns exhibit very curious carvings. Earlier than any already mentioned is that of St Gervase of Rouen, considered by E. A. Freeman "the oldest ecclesiastical work to be seen north of the Alps." It is apsidal, and in its walls are layers of Roman brick. It is said to contain the remains of two of the earliest apostles of Gaul--St Mello and St Avitian. There are numerous crypts in Germany. One at Gottingen may be mentioned, where cylindrical shafts with capitals of singular design support "vaulting of great elegance and lightness" (Fergusson), the curves being those of a horseshoe arch. The crypts of the cathedrals or churches at Halberstadt, Hildesheim and Naumburg also deserve to be noticed; that of Lubeck may be rather called a lower choir. It is 20 ft. high and vaulted.

The Italian crypts, when found, as a rule reproduce the "confessio" of the primitive churches. That beneath the chancel of S. Michele at Pavia is an excellent typical example, probably dating from the 10th century. It is apsidal and vaulted, and is seven bays in length. That at S. Zeno at Verona (c. 1138) is still more remarkable; its vaulted roof is upborne by forty columns, with curiously carved capitals. It is approached from the west by a double flight of steps and contains many ancient monuments. S. Miniato at Florence, begun in 1013, has a very spacious crypt at the east end, forming virtually a second choir. It is seven bays in length and vaulted. The most remarkable crypt in Italy, however, is perhaps that of St Mark's, Venice. The plan of this is almost a Greek cross. Four rows of nine columns each run from end to end, and two rows of three each occupy the arms of the cross, supporting low stunted arches on which rests the pavement of the church above. This also constitutes a lower church, containing a _chorus cantorum_ formed by a low stone screen, not unlike that of S. Clemente at Rome (see BASILICA), enclosing a massive stone altar with four low columns. This crypt is reasonably supposed to belong to the church founded by the doge P. Orseolo in 977. There are also crypts deserving notice at the cathedrals of Brescia, Fiesole and Modena, and the churches of S. Ambrogio and S. Eustorgio at Milan. The former was unfortunately modernized by St Charles Borromeo. The crypt at Assisi is really a second church at a lower level, and being built on the steep side of a hill is well lighted. The whole fabric is a beautiful specimen of Italian Gothic, and both the lower and upper churches are covered with rich frescoes.

Domestic crypts are of frequent occurrence. Medieval houses had as a rule their chief rooms raised above the level of the ground upon vaulted substructures, which were used as cellars and storerooms. These were sometimes partially underground, sometimes entirely above it. The underground vaults often remain when all the superstructure has been swept away, and from their Gothic character are frequently mistaken for ecclesiastical buildings. The older English towns are full of crypts of this character, now used as cellars. They occur in Oxford and Rochester, are very abundant in the older parts of Bristol, and, according to J. H. Parker, "nearly the whole city of Chester is built upon a series of them with the Rows or passages made on the top of the vaults" (_Domestic Architecture_, iii. 91). The crypt of Gerard's Hall in London, destroyed in the construction of New Cannon Street, figured by Parker (_Dom. Arch._ ii. 185), was a beautiful example of the lower storey of the residence of a wealthy merchant of the time of Edward I. It was divided down the middle by a row of four slender cylindrical columns supporting a very graceful vault. The finest example of a secular crypt now remaining in England is that beneath the Guildhall of London. The date of this is early in the 15th century--1411. It is a large and lofty apartment, divided into four alleys by two rows of clustered shafts supporting a rich lierne vault with ribs of considerable intricacy. There is a fine vaulted crypt of the same date and of similar character beneath St Mary's Hall, the Guildhall of the city of Coventry. (E. V.)

CRYPTEIA (Gr. [Greek: kryptein], to hide), a kind of secret police in ancient Sparta, founded, according to Aristotle, by Lycurgus; there is, however, no real evidence as to the date of its origin. The institution was under the supervision of the ephors, who, on entering office, annually proclaimed war against the helots (serf-class) and thus absolved from the guilt of murder any Spartan who should slay a helot. It was instituted primarily as a precaution against the ever-present danger of a helot revolt, and secondarily perhaps as a training for young Spartans, who were sent out by the ephors to keep watch on the helots and assassinate any who might appear dangerous. Plato (_Laws_, i. p. 633) emphasizes the former aspect, but there can be little doubt that, at all events after the revolt of 464 (see Cimon), its more sinister purpose was predominant, as we may gather from the secret massacre of 2000 helots who, on the invitation of the ephors, claimed to have rendered distinguished service (Thuc. iv. 80).

See HELOTS; EPHOR; also A. H. J. Greenidge, _Handbook of Gk. Const.
Hist._ (London, 1896); G. Gilbert, _Gk. Const. Antiq._ (Eng. trans.,
London, 1895).

CRYPTOBRANCHUS, a genus of thoroughly aquatic, but lung-breathing tailed Batrachia, of the family _Amphiumidae_, characterized by a heavy, flattened build, a very porous tubercular skin, with a frilled fold along each side, short stout limbs with four very short fingers and five very short toes, and minute eyes without lids. The vertebrae are biconcave, and although the gills are lost in the adult, ossified gill-arches, two to four in number, persist. A strong series of vomerine teeth extends across the palate. Three species of this genus are known. One is the well-known fossil of Oeningen first described as _Homo diluvii testis_ and shown by Cuvier to be nearly related to the gigantic salamander of Japan, _Cryptobranchus maximus_, which has since been found to inhabit China also; the third is the hellbender, mud-puppy or water-dog of North America, _C. alleghaniensis_, also known under the name of _Menopoma_. Both the fossil _C. scheuchzeri_ and _C. maximus_ grow to a length of over 5 ft. and are by far the largest Urodeles known, whilst _C. alleghaniensis_ reaches the respectable length of 18 in.

The eggs are laid in rosary-like strings. They have been found, in Japan, deposited in deep holes in the water, where they form large clumps (70 to 80 eggs) round which the female coils herself. The gigantic salamander has also bred in the Amsterdam zoological gardens, the eggs numbering upwards of 500; the male, it is stated, took charge of the eggs, and for the ten weeks which elapsed before the release of the last larva, he kept close to them, at times crawling among the coiled mass of egg-strings or lifting them up, evidently for the purpose of aeration. The larva on leaving the egg is about an inch long, provided with three branched external gills on each side, and showing mere rudiments of the four limbs.

CRYPTOGRAPHY (from Gr. [Greek: kryptos], hidden, and [Greek: graphein], to write), or writing in cipher, called also steganography (from Gr. [Greek: stegane], a covering), the art of writing in such a way as to be incomprehensible except to those who possess the key to the system employed. The unravelling of the writing is called deciphering. Cryptography having become a distinct art, Bacon (Lord Verulam) classed it (under the name _ciphers_) as a part of grammar. Secret modes of communication have been in use from the earliest times. The Lacedemonians had a method called the _scytale_, from the staff ([Greek: skytale]) employed in constructing and deciphering the message. When the Spartan ephors wished to forward their orders to their commanders abroad, they wound slantwise a narrow strip of parchment upon the [Greek: skytale] so that the edges met close together, and the message was then added in such a way that the centre of the line of writing was on the edges of the parchment. When unwound the scroll consisted of broken letters; and in that condition it was despatched to its destination, the general to whose hands it came deciphering it by means of a [Greek: skytale] exactly corresponding to that used by the ephors. Polybius has enumerated other methods of cryptography.

The art was in use also amongst the Romans. Upon the revival of letters methods of secret correspondence were introduced into private business, diplomacy, plots, &c.; and as the study of this art has always presented attractions to the ingenious, a curious body of literature has been the result.

John Trithemius (d. 1516), the abbot of Spanheim, was the first important writer on cryptography. His _Polygraphia_, published in 1518, has passed through many editions, and has supplied the basis upon which subsequent writers have worked. It was begun at the desire of the duke of Bavaria; but Trithemius did not at first intend to publish it, on the ground that it would be injurious to public interests. A _Steganographia_ published at Lyons (? 1551) and later at Frankfort (1606), is also attributed to him. The next treatises of importance were those of Giovanni Battista della Porta, the Neapolitan mathematician, who wrote _De furtivis litterarum notis_, 1563; and of Blaise de Vigenere, whose _Traite des chiffres_ appeared in Paris, 1587. Bacon proposed an ingenious system of cryptography on the plan of what is called the double cipher; but while thus lending to the art the influence of his great name, he gave an intimation as to the general opinion formed of it and as to the classes of men who used it. For when prosecuting the earl of Somerset in the matter of the poisoning of Overbury, he urged it as an aggravation of the crime that the earl and Overbury "had cyphers and jargons for the king and queen and all the great men,--things seldom used but either by princes and their ambassadors and ministers, or by such as work or practise against or, at least, upon princes."

Other eminent Englishmen were afterwards connected with the art. John Wilkins, subsequently bishop of Chester, published in 1641 an anonymous treatise entitled _Mercury, or The Secret and Swift Messenger_,--a small but comprehensive work on the subject, and a timely gift to the diplomatists and leaders of the Civil War. The deciphering of many of the royalist papers of that period, such as the letters that fell into the hands of the parliament at the battle of Naseby, has by Henry Stubbe been charged on the celebrated mathematician Dr John Wallis (_Athen. Oxon._ iii. 1072), whose connexion with the subject of cipher-writing is referred to by himself in the Oxford edition of his mathematical works, 1689, p. 659; as also by John Davys. Dr Wallis elsewhere states that this art, formerly scarcely known to any but the secretaries of princes, &c., had grown very common and familiar during the civil commotions, "so that now there is scarce a person of quality but is more or less acquainted with it, and doth, as there is occasion, make use of it." Subsequent writers on the subject are John Falconer (_Cryptomenysis patefacta_), 1685; John Davys (_An Essay on the Art of Decyphering: in which is inserted a Discourse of Dr Wallis_), 1737; Philip Thicknesse (_A Treatise on the Art of Decyphering and of Writing in Cypher_), 1772; William Blair (the writer of the comprehensive article "Cipher" in Rees's _Cyclopaedia_), 1819; and G. von Marten (Cours _diplomatique_), 1801 (a fourth edition of which appeared in 1851). Perhaps the best modern work on this subject is the _Kryptographik_ of J. L. Kluber (Tubingen, 1809), who was drawn into the investigation by inclination and official circumstances. In this work the different methods of cryptography are classified. Amongst others of lesser merit who have treated of this art may be named Gustavus Selenus (i.e. Augustus, duke of Brunswick), 1624; Cospi, translated by Niceron in 1641; the marquis of Worchester, 1659; Kircher, 1663; Schott, 1665; Ludwig Heinrich Hiller, 1682; Comiers; 1690; Baring, 1737; Conrad, 1739, &c. See also a paper on _Elizabethan Cipher-books_ by A. J. Butler in the Bibliographical Society's _Transactions_, London, 1901.