Chapter VI: Part II: Trap-Door Spiders (1)

It is now one hundred and sixteen years since Patrick Browne gave an illustration in his _Civil and Natural History of Jamaica_[43] of the nest of a trap-door spider, the first record of the kind with which I am acquainted. Seven years later the careful observations of the Abbé Sauvages appeared,[44] in which he gave a very good description of the nests of the "araignée maçonne" (_Nemesia cæmentaria_), which he discovered near Montpellier, likening them to little rabbit burrows lined with silk and closed by a tightly-fitting moveable door. In 1778 and 1794 Rossi[45] published an interesting account of the nest and habits of a trap-door spider which he had observed in Corsica and near Pisa; and from that time up to the present day the curious dwellings of these creatures, many species of which have been discovered in warm climates, have continued to attract the attention of naturalists.

[Footnote 43: P. 420, tab. 44, fig. 3 a. This work was published in London in 1756.]

[Footnote 44: In Histoire de l'Acad. Royale des Sciences (Paris 1763), p. 26-30.]

[Footnote 45: Rossi (P.), Osservazione Insettologische (Memorie di Matematica e Fisica della Società Italiana, vol. iv. (1778), and Fauna Etrusca, vol. ii. (1794)).]

Very little, however, has been added to our knowledge of the life-history of these remarkable architects for several years past, and, indeed, I think it may be safely asserted that the study of the habits and interdependence of the members of the animate world has not, during the last fifty years, made anything like a corresponding progress to that which may be seen in classification and description. The microscope has led many who, a century ago, would have found their chief delight in observing those points in the habits and external characters of living creatures which the naked eye could readily seize upon, to look much closer, to anatomize and describe in detail every organism, great and small, and to examine every tissue and cell.

It is, however, to the materials now being amassed by these modern "cabinet naturalists" that recourse must be had if we wish to form a true comprehension of the functions and habits of living things. They must tell us, for example, what instruments, tactile and visual, an animal possesses if we wish to understand how it constructs a particular fabric, so that the "field naturalist" will have to apply to his brother of the "cabinet" before he can turn his observations to good account.

Still, the fact remains that the habits of plants and animals afford many openings for careful investigation, and such as are especially within the reach of those lovers of nature who have ample time at their disposal, and the opportunity to spend it in a warm climate where life abounds, and is never wholly checked even in the depth of winter. It seems strange to think that collectors so frequently take creatures out of wonderfully constructed nests and yet never observe, or at any rate never describe, the structure of these fabrics. Thus, for example, the dwellings of only eight out of the thirty-six species of trap-door spider stated by Prof. Ausserer[46] to belong to the Mediterranean region are known in books, those of the remaining twenty-eight being, as far as I have been able to learn, yet to be discovered. This is the more strange as from the nocturnal habits of these creatures it is almost always necessary to dig them out of their nests; indeed it is more than probable that if all the dwellings which have been destroyed had been described, the following pages would never have appeared.

[Footnote 46: Prof. Ausserer (Anton.), Beiträge zur Kenntniss der Arachniden Familie der Territelariæ (Mygalidæ), in Verhandlungen der k.k. Zool. Bot. Gesellschaft in Wien. Jahrg. 1871, Band xxi.]

Before proceeding to pass briefly in review what has been written on the subject of trap-door spiders, it will be well to take one glance at the relation which these spiders bear to their fellows. The great order of spiders (_Araneæ_) has recently[47] been divided into seven sub-orders, the fourth of which, _Territelariæ_, includes all the trap-door spiders, and some others which do not construct trap-doors. This sub-order corresponds with that which was formerly called _Mygalidæ_, but this name, as well as that of _Mygale_, originally given to all trap-door spiders, has been abandoned because this latter name had previously been applied to a genus of Mammals, and it was feared that confusion might arise.

[Footnote 47: Thorell, On European Spiders, in Nova Acta Reg. Soc. Scient. Upsaliensis, ser. iii. vol. vii. fasc. 1 and 2 (1869-70).]

The _Territelariæ_ [or underground weavers] are distinguished from all other spiders by the position of their falces,[48] which have the fang directed downwards, and move vertically parallel to one another. Thus when a victim is seized by one of the _Territelariæ_ it receives a downward blow, while other spiders strike sideways, the falces moving in a horizontal or oblique direction. With very few exceptions this sub-order may also be known by the presence of four blotches of paler colour at the base of the abdomen underneath, indicating the position of four air-sacs, almost all, or indeed perhaps all, other spiders having but two.

[Footnote 48: Sometimes called mandibles. One of these is represented, enlarged, at Fig. A 7. in Plate VII., p. 88.]

Certain species of _Territelariæ_ are the only spiders known to construct nests closed with a door, and these creatures must be admitted to rank among the first of Nature's handicraftsmen and inventors.

The geometrical webs of many common spiders are very beautiful structures, but these are for the most part only snares for prey, and not permanent dwellings, although the cocoons in which the eggs are placed are often most ingeniously contrived. Thus in the south we may sometimes find an inverted balloon of strong silk about an inch long attached to heath and other bushes, which, if examined during the winter, will be found to contain in its centre a case enclosing a mass of eggs about one-third the bulk of the entire cocoon. This inner case is shaped exactly like the outer, and both have a circular silk lid carefully closed, and the space between the two is filled with a dense mass of golden-brown silk, which acts no doubt as an excellent non-conductor. This cocoon is the work of _Epeira fasciata_, a species apparently only found in southern Europe.

Other spiders again, such as _Theridion_,[49] suspend by a long and delicate cord of silk a minute balloon, scarcely larger than a seed-pearl, containing their eggs, which sways to and fro in the lightest breath of air. But admirable as these cocoons and geometrical snares are, the homes of these and of spiders generally do not exhibit much contrivance or ingenuity, or cannot at any rate be ranked in the same category as those of the trap-door spider. But it may be asked, why should we admire the one more than the other, since it is clear that the most squalid and mean-looking nest exactly serves the purpose of its occupant, whether for shelter or defence, and in many cases a spider might even say with truth that as for her home it would not be so safe if it were not so dirty.

[Footnote 49: _Theridion variegatum_ (Bl.). _Ero tuberculata_, Koch.]

But the answer is simple: the trap-door spider's dwelling is to that of common spiders what the Mont Cenis tunnel is to other tunnels, and something besides.

What delights us is to see how by clever contrivance and great perseverance new and multiplied difficulties have been overcome, and dangers avoided, and the interest aroused is exactly proportionate to the amount of these difficulties and dangers.

It is hoped that the following pages and their accompanying illustrations will vindicate the claims of these spiders to the marked attention and admiration which is here asserted to be their due as architects and engineers.

There is but one British or North European representative of the _Territelariæ_--namely, _Atypus piceus_ (or _Sulzeri_),[50] and this creature does not appear to deserve the name of trap-door spider, for in three nests which M. H. Lucas kindly showed me, preserved at the Jardin des Plantes at Paris, the mouth of the tube was destitute of any covering. I gathered from what I saw, and from what M. Lucas told me, that these nests [which he had taken in the neighbourhood of Paris], consist of a silk tube from eight to ten inches long, of which about one inch only at the lower extremity penetrates the earth, the remainder being carried upwards in an irregular and sinuous course among the stems and leaves of small plants and grasses to which it is attached. When the tube is removed from these supports it collapses, and appears like a rather coarsely woven ribbon-shaped strip of silk.[51]

[Footnote 50: Unless it should prove, as Prof. Ausserer suggests, that the British _Atypus_ is distinct from the Continental, when it would bear the name of _Atypus Blackwallii_. (Ausserer, l. c. p. 17).]

[Footnote 51: I have never been able to meet with an English specimen of the nest of _Atypus_; but it would appear from the descriptions that the English differ from the French nests in being subterranean, and in having the mouth of the tube concealed by a loose flap of silk. Mr. Blackwall says: [Spiders of Great Britain and Ireland, part i. p. 14] "Dr. Leech has taken specimens of _Atypus Sulzeri_ in the vicinity of London and Exeter. It excavates, in humid situations, a subterraneous gallery, which is at first horizontal, but inclines downwards towards its termination. In this gallery it spins a tube of white silk, of a compact texture, about half inch in diameter.... Part of the tube hangs outside of the aperture to protect the entrance."

It would be interesting to learn whether these differences permanently distinguish the English from the French nests, and if so, whether the spiders which construct them are not, as Prof. Ausserer is inclined to believe, distinct also.]

Four types of trap-door nest, properly so called, may now be distinguished in the world at large, and these are represented diagrammatically in the following woodcut.[52]

[Footnote 52: Where all the figures, except C 1, and D 1, which are of the natural size, are reduced to about one-third of the actual size in large specimens.]

Of these two only (A and B) were known up to the present time, the construction of which is much simpler than that of the two new types (C and D), which I have hitherto only found at Mentone and Cannes.[53]

[Footnote 53: It must not be supposed that I have a sole or prior claim to what may prove to be new and of interest in the following observations on the Trap-door Spiders of the Riviera. This priority belongs to the Hon. Mrs. Richard Boyle, to whom I owe it that I ever took up the subject. It was, thanks to her guidance, that I first became acquainted with these marvellously-concealed nests in their native haunts, and to her active help that I finally arrived at a comprehension of the different types of structure which they present.]

It will be seen at a glance that A and B have but one door, while C and D have two, these latter having a surface door, and also another door a short way under ground.

All the nests consist of a tube excavated in the earth to a greater or less depth, unbranched in all but D, and in every case lined with silk, this lining being continuous with the lining of the door or doors of which it forms the hinge.

I have found it convenient to distinguish these four types of nests by the following names:--A, the single door cork nest, or shortly the cork nest; B, the single door wafer nest; C, the double door unbranched nest; and D, the double door branched nest.

The type B has only been found in the West India Islands, and is chiefly distinguished from A by having a thin and wafer-like door, wholly constructed of silk, without admixture of earth, lying on rather than fitting into the aperture of the tube; while in A the door is much thicker, made of layers of earth and silk, and so contrived that it tightly closes the mouth of the tube, which is bevelled to receive it, much as a cork closes the neck of a bottle.[54]

[Footnote 54: Nests belonging to the type A, are represented in Plates VII., p. 88, and VIII., p. 94.]

The West Indian nests are of a much tougher and coarser texture than those which I have seen in Europe, and vary somewhat in the shape of their tube, which is curved or straight, and sometimes has near its lower extremity a short spur-shaped enlargement, giving to the whole a ludicrous resemblance to a stocking, of which this spur is the heel.

Mr. Gosse,[55] in his _Naturalist's Sojourn in Jamaica_, has given an admirable description of one of these single door wafer nests, the work of _Cteniza nidulans_, which I cannot do better than quote:--

[Footnote 55: Gosse (P. H.), Naturalist's Sojourn in Jamaica (1851), p. 115-118. See also for another description of the same nest Latreille's Vues Générales sur les Araneides, in the Nouv. Ann. du Muséum (Paris, 1832), tom. i. p. 73-4.]

The nest is "cylindrical, or nearly so, from four to ten inches deep, and about one inch in diameter; the bottom is rounded; and the top, which is at the surface of the soil, is closed very accurately with a circular lid. They are not all equally finished, some being much more compact, and having the lid more closely fitted than others. Some have irregular bulgings, and ragged laminated offsets on the outer surface; but all are smooth and silky on the inside.... The mouth of the tube, and the parts near it, are very strong; the walls here often having a thickness of from one-eighth to one-fourth of an inch; but the lower parts are much thinner. The lid is continuous with the tube for about a third of its circumference, and this part may be called the hinge, though it presents no structure peculiar to itself; it is simply bent at a right angle, as is manifest, if a nest be cut longitudinally through with scissors, the incision passing through the midst of the lid. The mode of construction, I judge, from examination of many nests, to be this. The spider digs a cylindrical hole in the moist earth, with her jointed fangs or mandibles, carrying out the fragments as they are dislodged. When the excavation has proceeded a little way, she begins to spin the lining which forms the dwelling. I conclude thus, because nests are occasionally found a few inches in length, with the lid and upper part perfect, but without any bottom, these being evidently in the course of formation. I suppose that she weaves her silk at first in unconnected patches, against the earthy sides, perhaps where the mould is liable to fall in; and thus I account for the loose rough laminæ of silk that are always found projecting from the outer surface. These are overlaid with other patches more and more extensive, until the whole interior walls are covered; after which the silk is spun evenly and continuously all round the interior, in successive layers of very dense texture, though thin. Under the microscope, with a power of 220 diameters, these layers are resolved into threads laid across each other and intertwined in a very irregular manner; some are simple, varying from 1/7000 to 1/2000 of an inch in diameter, and others are compound, several threads, in one part separate, being united into one of greater thickness which cannot then be resolved.... The mouth of the tube is commonly dilated a little, so as to form a slightly recurved brim or lip; and the lid is sometimes a little convex internally, so as to fall more accurately into the mouth and close it.

"The thickening of the hinge by additional layers is, I think, accidental only, as, out of the many specimens that I have examined, only one or two had such a structure. In the neatest examples, the lid is of equal thickness throughout its extent, agreeing also with the walls for the first few inches of their depth."

Mr. Gosse says that he possesses one specimen of peculiar compactness, which differs from all the others that he has examined in having "a row of minute holes, such as might be made by a very fine needle, pierced around the free edge of the lid, and a double row of similar ones just within the margin of the tube. There are about fifteen or sixteen punctures in each series, and they penetrate through the whole substance, the light being clearly seen through each hole. I do not think, as I have somewhere seen suggested, that they are intended to afford a hold for the spider's claws when she would keep her door shut against the efforts of an enemy, for what would be the use of having them in the tube _close to the lid_, so close that not the eighth of an inch intervenes between the surface of the lid and that of the tube, when the former is tightly closed? I would suggest whether they may not be air-holes, for so tight is the fitting of the lid, and so compact the texture of the material, that I should suppose the interior would be impermeable to air but for this contrivance."[56] "The spider that inhabits this nest is black, with the thorax of an exceedingly lustrous polish, its abdomen is full and round, its legs very short."

[Footnote 56: I cannot myself think this explanation probable, and should still be inclined to consider these punctures to be the claw marks of the spider, as is the case in some European nests.]

Another form of this single door wafer nest is described by Mr. Sells,[57] in which there is a hinge-like thickening of the silk lining of the tube about an inch below the actual hinge of the door, which it is suggested may serve to give additional elasticity. This was not found, however, in all the nests examined, and Mr. Sells conjectures that in newly constructed nests the lid may close sufficiently firmly without this contrivance, and that it is only added in older nests.

[Footnote 57: Mr. W. Sells. Notes respecting the Nest of _Cteniza nidulans_, in Trans. Ent. Soc. ii. 207-210.]

Patrick Browne's figure, to which reference has been made above, represents a nest with two doors, one applied against the other, at the mouth of the tube, and it has often been asked what this could possibly mean.

Some have thought that the drawing was fanciful, others that it was made from an abnormal or injured nest. However, I believe that the drawing, though rude, is, in fact, not very incorrect, and shows a case of repair or enlargement of the nest, a subject to be treated of more fully further on. There is a specimen exhibited in the British Museum which in this respect very nearly corresponds with Browne's figure; it is labelled "Nest of Trap-door Spider with two doors, from the spider having enlarged its abode.--Jamaica." Here one sees that the spider has prolonged its tube about half an inch beyond the original mouth of the nest, where it has constructed a new mouth and door, the old door standing straight up at the back of and behind the new one.

I imagine that the explanation of this curious piece of cobbling may be somewhat as follows:--When the nest was in its original state and had but one door, this door became by some accident covered over with earth to about the depth of half an inch, and the inmate was thus imprisoned. Then the spider, being, like most other members of its order, very unwilling to abandon its home, determined to clear away the entrance to its nest, and to lengthen the tube so that it should reach up to the new level of the surface of the earth.... If I am right, this should rather be called a lengthening than an enlargement of the tube.

The nests of the cork type (A, p. 79) may usually be distinguished at a glance from those of the wafer type by the greater thickness of the door, and by its manner of shutting, but a nest from Morocco has been figured and described by Prof. Westwood,[58] which seems intermediate between the two. The door in this case may perhaps be considered as of the cork type, though it is very thin, for it does fit into the mouth of the tube, which is bevelled to receive it.

[Footnote 58: Observations on the Species of Trap-door Spiders, in Trans. of Entomological Soc., London, 1841-3, vol. iii. p. 175.

I wish to take the present opportunity of thanking Prof. Westwood for having afforded me special facilities for examining this and other specimens forming part of the very valuable collections under his care at Oxford.]

These nests were forwarded with their living occupants (_Cteniza [Actinopus] ædificatorius_) from Tangiers to Prof. Westwood, who describes the nests as being "about four inches deep, slightly curved within, about three quarters of an inch in diameter, the valve at the mouth not being circular, but rather of an oval form, one side where the hinge is placed being straighter than the other. The valve is formed of a number of layers of coarse silk, in the upper layers of which are imbedded particles of the earth, so as to give the cover the exact appearance of the surrounding soil, the several successive layers causing it, when more closely inspected, to resemble a small flattened oyster-shell."

The resemblance between this nest and that of the West Indian species is the more interesting as Prof. Westwood says that both belong to the same genus, (_Cteniza_ or _Actinopus_ of different authors,) and are so closely allied as to present scarcely any important distinction but that of size.

We shall find, however, on comparing the nests of these trap-door spiders and their occupants, that we cannot as yet make any rule as to the kind of nest which we may expect from a given spider.

It will be seen that species belonging to the same genus, and closely resembling one another, sometimes build dissimilar nests; while others, belonging to different genera, and unlike in many important respects, construct almost identical nests.

This is the more strange, because, if we examine the structure of the claws and palpi, they often seem to be specially adapted to serve as carding instruments and to play a very important part in the weaving of the silk linings of the nest; and yet nests of the same type are occasionally produced by spiders in which these appendages are quite unlike, and dissimilar nests where the claws and palpi are to all appearance identical.

Thus, for example, if the reader will examine the drawings of part of the foremost right foot of _Cteniza fodiens_, figs. A, 9 and 10, Plate VII., p. 88, with that of _Nemesia cæmentaria_, figs. A, 9 and 10, Plate VIII., p. 94, both of which make nests of the cork type, he will see that in the former the last joint of the tarsus is armed along the inner side, with many moveable spines, and that each of the two curved terminal claws has only one very strong tooth near the base; while the same joint of the latter (_N. cæmentaria_) has no spines, and the claws have three minute comb-like teeth near the base.

On the other hand, in the reverse case, where the structure of the same joint is very similar, the nests may be wholly unlike, as in _Nemesia Eleanora_, Plate XII., p. 106, and _N. cæmentaria_, Plate VIII., where the nest of the former is of the double-door unbranched type, and that of the latter of the single-door cork type.

It is probable however that a fuller and closer comparison of, and a more exact acquaintance with the several parts and their functions might show us that all spiders which spin similar webs are furnished with equivalent instruments, so that what one leg lacks another may possess in some shape or another; brushes of stiff hairs in one place, compensating for a toothed claw, or for a row of moveable spines in another.[59]

[Footnote 59: The claws are probably of first-rate importance in this respect and should be most carefully studied. M. Lucas has stated that the claws of _Mygale Blondii_, and _M. nigra_ from Algiers, and of _M. nigra_ and _M. avicularia_ from Brazil, are retractile like those of a cat! Unfortunately the dwellings of these spiders have not been described. See Lucas (H.) in Rev. et Mag. de Zoologie, sér. 2, tom. ix. 1857, p. 587, and Ann. de la Soc. Entom. de France, ser. 3, tom. v. p. cxx., and vi. p. clxxi. Another curious point in which spiders differ is the presence or absence of viscidity in the hairs which clothe their feet and palpi. Mr. Blackwall states (Spiders of Great Britain and Ireland, vol. i. p. 13), that by far the greater number of the sub-order _Territelariæ_, or _Mygalidæ_ as he terms them, "have the inferior surface of their biungulate tarsi, and of the digital joint of their pediform palpi, in the females, densely clothed with compound, hair-like papillæ, constituting an apparatus which, by the emission of a viscous secretion, enables them to traverse the perpendicular surfaces of dry, highly polished bodies; others have three pairs of spinners and are destitute of hair-like papillæ on the legs and palpi."

The four species of trap-door spider on the Riviera, here described, appear to form exceptions to this rule, however, for they all remained helpless prisoners when placed in a glass tumbler, though struggling vigorously for freedom.

When, however relying on this experience, I placed a number of smaller spiders of different kinds in glasses for examination some walked straight out without any difficulty, while others were unable to climb up the sides.]

It would be interesting, from this point of view, to draw all the parts which may be supposed to aid in the act of weaving, and so to contrast the corresponding limbs of different spiders, the nests of which are known, that one might see at a glance in what they differed and agreed. I have done this for the falces and the last joint of the foremost right foot of the four spiders figured in Plates VII., VIII., IX., and XII., but to make the case complete all the limbs should be represented in the same way.

Of the two spiders which are shown with their cork nests in Plates VII. and VIII., the purplish grey _Cteniza fodiens_, (Plate VII.) appears to be much rarer than the brown striped _Nemesia cæmentaria_ (VIII.), at any rate at Mentone. I have hitherto only succeeded in obtaining four specimens of the former, though I have searched repeatedly for them at Cannes and Mentone, while the latter species is tolerably common.

The nests are, however, often extremely hard to find, and in some cases it is only by chance that I have been able to light upon them. All these trap-door spiders seem usually to prefer rather moist and shady places, and sloping banks or loose terrace walls where the interstices between the stones are filled up with earth, and concealment is afforded by the creeping lycopodium (_Selaginella denticulata_), Ceterach, spleen-wort or maiden-hair ferns, with short moss and splashes of white lichen to distract the eye.

It was from such a terrace wall at Mentone, on March 26, 1872, that the nest A in Plate VII. was taken, the tube running obliquely back into the earth between the stones, and the door being concealed by a net-work of lycopodium, one spray of which had been allowed to grow on its upper surface.

The tubes of these as of the other kinds of nest are sometimes straight, but more frequently they are bent, and almost always take a downward course.

The following is Mr. Pickard-Cambridge's description[60] of _Cteniza fodiens_, the spider which constructs this nest.

[Footnote 60: The following description and remarks, printed in a different type, have been kindly prepared for this work by the Rev. O. Pickard-Cambridge, to whom I sent a series of specimens of the spiders preserved in spirit of wine and their nests. My very sincere thanks are due to Mr. Pickard-Cambridge for this assistance, which will give to my publication a value in the eyes of Arachnologists which it could not otherwise have possessed. To all those who wish to study the true structural relations of the four spiders, the habits of which are recorded in the following pages, these details will prove of the highest importance; while those who are only interested in the economy of these creatures can readily pass them over. For observers in the field there is a very ready way of knowing these four spiders apart, as it will be seen that when they are somewhat alike the nests are different (_Nemesia meridionalis_ and _N. Eleanora_), and when the nests are alike (_Cteniza fodiens_ and _Nemesia cæmentaria_) the spiders are markedly dissimilar.]

FAM. THERAPHOSIDES.

Gen. Cteniza, Latr.

Cteniza fodiens. Plate VII.

Syn. _Mygale fodiens_, Walck. _Ins. Apt._, i. p. 237.

_M. Sauvagei_, Ausserer, _Beiträge zur Kenntniss der Arachniden
Familie der Territelariæ (Thor.)_, p. 36.

Female adult length 10 lines.

_Cephalothorax_ oblong oval, somewhat truncate at each end, and of
a dull whitish-yellow brown colour, the normal grooves and furrows
are strongly marked, the caput is large and elevated, rounded on
the sides and slightly higher near the occiput than at the ocular
area, the junction of the thoracic segments is indicated by a
strong deep curved indentation, the curve directed backwards;
there are a few strong black bristles of different lengths within
the ocular space, and several others run backwards in the central
line to the occiput. The height of the Clypeus is equal to rather
more than the diameter of one of the foremost eyes. The _Eyes_ are
eight, and form a rectangular figure whose transverse diameter
is the longest, and whose fore side is a little shorter than
the hinder one; the longitudinal diameter is about equal to the
space between the two foremost eyes; these are the largest of the
eight, and are separated by an interval of very nearly two eyes'
diameters; the two central eyes are the smallest, and are distant
from each other just about one eye's diameter, the eyes of the
hinder row are in two pairs forming the hinder corners of the
rectangle, those of each pair are nearly contiguous to each other,
and the inner one of each is the smallest; these last in the figure
appear to be the smallest of the eight, but this arises from the
point of view whence the figure was drawn; the two central eyes
occupy as nearly as possible the centre of the figure formed by the
two foremost eyes, and the two inner ones of the hinder row, and
are seated on a large black spot. The _Legs_ are short, strong,
and similar to the Cephalothorax in colour, their relative length
appeared to be 4, 3, 1, 2, they are furnished with hairs, bristles,
and short strong spines. These latter are on those of the two first
pairs, situated chiefly in two longitudinal parallel rows beneath
the tibiæ, metatarsi, and tarsi; on those of the third pair they
are situated on the sides and upper sides of those joints, while
the fourth pair has them only beneath the metatarsi and tarsi; all
the tarsi terminate with three claws, the two superior ones are
much the longest and strongest, and have a single short strong
tooth inside near the base. Near the union of the femora and genuæ
of the legs of the fourth pair are numerous short strong spines,
hairs, and bristles. The _Palpi_ are similar in colour to the
legs; they are strong and about equal in length to the legs of the
second pair, and have a double longitudinal row of strong spines
widely separated and divergent from each other beneath them; the
digital joint (like the tarsi of the legs) is furnished with other
spines between these two rows; each palpus terminates with a single
untoothed curved claw. The _Falces_ are strong, prominent, rounded
in the profile line, and have some hairs, bristles, and spines near
their fore extremities; the longest and strongest of the spines
are three in number, and form a kind of transverse row or comb at
the extreme inner point on the upper side of each falx; besides
these there is a row of short tooth-like spines on either margin of
the furrow on the under side of each falx in which the fang lies
concealed when at rest. The _Maxillæ_ are short and strong; the
palpi issue from their extremity on the outer side, and the inner
extremity is somewhat prominent and pointed.

The _Labium_ is small, short, somewhat rectangular in form, and
broader than high; the apex is a little rounded, and furnished with
a single transverse row of small tooth-like spines.

The _Sternum_ is somewhat subtriangular in form, much broader
behind, where it is rounded on the outer angles.

The _Abdomen_ is short oval, very convex above, where it is of a
yellowish vinous brown colour, with a slightly darker longitudinal
tapering, indistinct central stripe on the fore part; it is
sparingly clothed with hairs, and the under side is of a pale dull
yellowish colour; the spinners are four in number, and those of the
superior pair are the strongest, three jointed and upturned.

Adults and immature examples (all females) were found in tubular
holes lined with silk and closed at the orifice with a strong solid
hinged lid, shutting into the opening like a cork.

The portions of nests at B and C in Plate VII. also belong to _Cteniza fodiens_, the latter being very similar to A in its surroundings, but having a rather thinner door, slightly hollowed out above (C 1). The smaller nest shown shut at B and open at B 1,[61] is admirably concealed by mosses and lichens, some of which actually grow upon the door, and here two minute trap-doors, belonging to infantine examples of a distinct species of spider (_Nemesia meridionalis_), are seen on the left hand below.

[Footnote 61: It must be clearly understood that when the doors are represented as standing open or ajar this is unnatural, as they always close by their own combined weight and elasticity.]

It is not rare to find small colonies of nests of the same or distinct species grouped closely together in this way, though I greatly doubt whether one can safely assume their sociability from this fact.

I have very seldom seen nests on the flat ground, where the door would lie horizontally when closed, a sloping or nearly vertical bank being usually chosen, where the door will fall to by its own weight.

In the Ionian Islands another species or variety of _Cteniza_, described under the name of _Cteniza (or Mygale) ionica_, and represented as being of an uniform yellow-brown colour, is said to make its nests in the earth of the terraces round the roots of the olive trees.

Mr. Saunders[62] gives admirable figures and descriptions which show us at once that these nests, which he discovered in rather elevated situations in the island of Zante, are of the cork type; but, in this case, the entire door does not shut flush with the surface, as in ordinary cork nests, but has a short spur-like projection above and behind the hinge, serving, as is conjectured, like a lever, by pressing on which from the outside the lid may easily be raised.[63] When I come to speak of the manner of constructing and repairing nests I shall have occasion to refer to these nests again.

[Footnote 62: Sydney Smith Saunders. Description of a Species of Mygale from Ionia, in Trans. Ent. Soc. London, 1839, vol. iii. p. 160, Plate IX.]

[Footnote 63: I must own to some hesitation about accepting this explanation, though I am not prepared to offer any other.]

I have not as yet found any nests on the Riviera which can be said to correspond accurately with those of _Ct. ionica_, the only builders of cork nests yet discovered in this district being _Cteniza fodiens_ and _Nemesia cæmentaria_.

This latter species is described by Mr. Pickard-Cambridge,[64] in the following terms:--

[Footnote 64: See above, p. 88.]

Gen. Nemesia (Savigny).

Nemesia cæmentaria. Plate IX.

Syn. _Mygale cæmentaria_ (Latr.), _H. N. des Crust._ t. vii. p. 164.

_M. cæmentaria_ (Walck), _Ins. Apt._ i. p. 135.

Female adult, length 9 to 11 lines.

_Cephalothorax_ rather elongate, oval, and somewhat truncated at
each extremity; the caput is elevated and rounded on the sides and
upper part, but less elevated than in _Cteniza_; the normal grooves
and indentations are well marked, and the junction of the cephalic
and thoracic segments is indicated by a strong deep impression or
cleft, of a transverse, curved, or somewhat bent angular form, the
curve or angle directed forwards. The colour of the cephalothorax
is yellow-brown tinged with olive, the margins are paler, but
have no distinctly defined marginal band. On the hinder part of
the caput are three clear brown-yellow longitudinal stripes; the
central one reaches from behind the two hind central eyes to the
thoracic junction, the lateral ones converge a little to the same
point, but do not reach nearly, in fact not much more than half
way, to the eyes. The clypeus is of a clear brown-yellow colour
also, and on either side of it (extending from each fore lateral
eye), is an irregular patch of the same. The ocular region and
clypeus are furnished with a few strongish black bristles, and the
three yellow stripes above mentioned have a few more, those on the
central stripe being the longest and strongest, and disposed in a
single longitudinal row.

The _Eyes_, eight in number, are seated on a transverse oval
eminence, and form a rectangular figure, whose transverse diameter
is double the length of its longitudinal diameter: their relative
position is similar to that of _Cteniza_, but in the present
species they are smaller than in _C. fodiens_: those of the hind
central pair are the smallest of the eight, and each is very
nearly contiguous to the hind lateral on its side; the interval
between those of each lateral pair is small; the space between
the two central eyes of the eight is equal to an eye's diameter,
and each of these is separated from the hind central and fore
lateral nearest to it by a similar interval. The _Legs_ are strong,
moderately long, their relative length 4, 1, 3, 2?, but little
difference is observable between 1, 3, and 2; they are furnished
with hairs, bristles, and a few, not very strong, spines; each
tarsus terminates with three curved claws, the two superior ones
much the longest and strongest, and have a few small teeth near
their base inside.

The _Palpi_ are strong and similar in colour and armature to the
legs; each is terminated with a curved black claw.

_Falces_ strong, prominent, and rounded in the profile line;
they are furnished with hairs, bristles, and strong tooth-like
spines; the four strongest of these latter form a transverse row
at the inner extremity of each; besides these there is a row of
short tooth-like spines on the inner margin of the furrow on the
underside of each falx, in which the fang lies concealed when at
rest. The _Maxillæ_ are strong, with a small angular prominence at
their inner extremities (when looked at from beneath), and each
has three to four small dark-coloured teeth in a short, straight,
obliquely transverse row at the base on the inner side. _Labium_
broad but short, its breadth is double its height, and the upper
corners are rounded off. The _Sternum_ is of a somewhat pentagonal
form.

_Abdomen_ rather elongate oval, tolerably, but not excessively,
convex above; it is of a dull yellowish whitey-brown colour marked
and mottled above with dark chestnut brown; the markings are rather
irregular, but a general disposition in the form of a longitudinal
central, and oblique lateral, stripes or bars may be traced on the
hinder half; the superior spinners are short and three-jointed,
those of the inferior pair are exceedingly minute.

Adult females were found in nests similar to those of _Cteniza
fodiens_.

The cork nests are the simplest form of nest, with the exception of those described above from Jamaica, and have constituted, up to the present time, the only type known in Europe. Their chief claims to our admiration lie in the perfection of workmanship which the doors usually exhibit, and the marvellous concealment which they afford when closed. These doors as a rule fit so tightly [thanks to the accurate adjustment of their sloping sides to the bevelled lip of the tube which receives them,] that they afford a certain amount of mechanical resistance, even when the spider is away. But, after examining a very large series of these cork nests, I find that there is some variation in the degree of perfection attained in their work by different individuals of the same kind. The mechanical resistance is greater or less in proportion to the thickness and weight of the door, and to the slope of its sides, and of the bevelled edges of the tube; and in each of these details a marked difference may be observed.

One might suppose from what has so often been repeated as to the habits of _N. cæmentaria_, that, whenever any one attempts to open the door, the spider, which is always at home in the day time, would dart up from the bottom of the tube and endeavour to keep it closed by holding on from within.

I cannot say what may take place during the summer months; but from October to May I have but rarely found one of these spiders ready to oppose me, though _Nemesia meridionalis_ and _N. Eleanora_ frequently did so. Many times, wishing to provoke them, I have tapped at the door in order to apprise the occupant of my arrival, or lifted it and let it fall again, and always in vain, though the spider was there, crouching at the bottom of her tube.

Indeed I can only recall six or eight instances in which this spider did hold down her door, and on three of these she was captured.

I will now relate what I saw on one of these occasions,[65] for there has been much speculation as to the manner in which the spider clings to the door and offers the determined resistance which is experienced.

[Footnote 65: Mrs. Boyle was the first to witness this curious sight, and my description of the resistance of the spider is almost an exact repetition of hers to me. It is curious also that, following her indications, I found the very nest and spider on which she had made her observations, and every detail recurred again though several days had elapsed between her visit and mine.]

No sooner had I gently touched the door with the point of a penknife than it was drawn slowly downwards, with a movement which reminded me of the tightening of a limpet on a sea-rock, so that the crown which at first projected a little way above, finally lay a little below the surface of the soil. I then contrived to raise the door very gradually, despite the strenuous efforts of the occupant, till at length I was just able to see into the nest, and to distinguish the spider holding on to the door with all her might, lying back downwards, with her fangs and all her claws driven into the silk lining of the under surface of the door. The body of the spider was placed across, and filled up, the tube, the head being away from the hinge, and she obtained an additional purchase in this way by blocking up the entrance.

I did not force the spider to release her hold, but, by a rapid stroke with a long-bladed knife, cut out the upper part of the tube with the surrounding mass of soil, and thus secured the trap-door and its owner. This specimen is represented at fig. C, Plate VIII., where the pin-point holes made by the claws may be seen in pairs round the whole circumference of the flatter portion of the lower surface of the door except on the side next to the hinge.

Whenever a spider resists in this way she must make these holes, but I have very rarely seen them in other nests; this may perhaps be accounted for by their having been effaced by the action of moisture which would stretch the silk. However this may be, this specimen showed the claw marks quite distinctly on my return to England after the lapse of several weeks.

Much has been written about these marks, which are frequently spoken of as holes purposely made in the silk in order to give the spider a better purchase. It has also been stated that two holes may be seen in the silk of the tube near the mouth on the side away from the hinge, but these I have never been able to find. The door of nest A in Plate VIII. is rather abnormal, as it is made up of two doors, the smaller one being spun into the top of the one now in use. This is, I believe, an abnormal and rather clumsy example of the ordinary way of enlarging the nest, but of this we shall see more when we come to speak of the construction and repairing of these nests generally.

Fig. B in this plate represents a moss-covered sod pierced by the tube of a nest, the door of which is entirely concealed from view, and only discovered when opened as at B 1.

This nest was found accidentally by Mr. Robert Lightbody, who kindly brought it to me, its presence having been betrayed by the tube, which he happened to cut through in digging up a plant. The moss on the door grew as vigorously, and had in every way the same appearance, as that which was rooted in the surrounding earth; and so perfect was the deception that I found it impossible to detect the position of the closed trap even when holding it in my hand. There can be no doubt that many nests escape observation in this way, and the artifice is the more surprising because there is strong reason to believe that this beautiful door-garden is deliberately planted with moss by the spider, and not the effect of a mere chance growth. I shall adduce evidence in support of this statement by-and-by.

I alluded to the nest C (Plate VIII.) when speaking of the claw marks which it exhibits, and that figured at D and D 1 in this plate is merely an instance of a good example of this type. I have taken nests of _N. cæmentaria_ both at Cannes and Mentone, and have little doubt that this species will be discovered at many points along the Riviera. I detected two abandoned nests of the cork type, which I fully expect had belonged to _N. cæmentaria_, in an enclosed space called the Campagne de Garonne in Marseilles itself. These nests lay in the little mound of undisturbed earth between the divided trunks of the small olive-trees, and I do not doubt that if I had had time to search I should have discovered more nests, and perhaps others which were still tenanted.

We now turn from the single-door nests to those with double doors, and from the well known to the new types of structure.

In these we have a thin and wafer-like door at the mouth of the nest, and from two to four inches lower down, a second and solid underground door. These lower doors are characteristic of the nests to which they belong, that of the branched nest (_Nemesia meridionalis_, Plate IX.) being long and more or less tongue-shaped, while that of the unbranched double-door nest (_N. Eleanora_, Plate XII. p. 106) is somewhat horse-shoe shaped.

The surface doors of these two kinds of nest do not appear to differ, and, though rather thinner, may be compared to those of the single-door wafer kind from Jamaica.

The commonest form at Mentone is the branched nest, which may be found in abundance in many of the loosely-built walls of the lemon and olive terraces or on sloping banks, but they are rarely to be met with on flat ground.

In the nests of _Nemesia meridionalis_ the tube, instead of being simple, as it is in all other known nests, is invariably branched, a second tube joining the first at the point where the lower door is hung and forming with it an angle of about 45°. The main tube descends and is frequently curved, or sometimes doubly bent like the spout of a tea-kettle (A, Plate X. p. 100), while the branch ascends, and in some few instances reaches the surface, though it is usually a _cul de sac_ (Plate IX.)

In the exceptional cases where the nests have two superficial openings, one of the two surface doors always appears neglected and going to decay, or is covered with earth which chokes the upper part of its tube. The explanation of this probably is that the spider found the original entrance blocked up or in some way unfitted for use, and then prolonged what was the blind branch until it reached the surface and replaced the former doorway. However this may be it is certain that in the great majority of nests it will be found that the branch ends in the earth, and is a _cul de sac_, and this I have invariably observed to be the case in the nests of very young spiders of this species (fig. B, Plate IX.)

The tube is frequently enlarged at the mouth, and forms a spreading lip which the surface door is usually large enough to cover (A 1, Plate IX.)

In these branched double-door nests the upper door does not fit into, but merely lies upon, the mouth of the tube, the elasticity of the hinge and its own weight being sufficient to keep it closed. The lower door is suspended by a hinge placed at the apex of the angle formed by the bifurcation of the tube, and is hung in such a manner that it can either be pushed upwards so as to lie diagonally across and block the main tube, or be drawn back so as to fit into and close the entrance to the branch.

This will, I think, best be understood by reference to the drawings of a small nest of this type given at B 1 and B 2 in Plate XI. p. 105, where the second door is shown in its two positions. This lower door is from 1 to 1-1/2 lines thick, channeled above, but nearly flat on the back, and of an elliptic form, with a loose appendage at its lower end, the whole being made of earth enclosed in a case of silk.[66] When the lower door is drawn back so as to close and conceal the entrance to the branch, it lies in the same plane, and closely corresponds in curvature with the lining of the main tube and almost appears to form part of it (fig. A, Plate X. p. 100, and fig. B 1, Plate XI. p. 105).

[Footnote 66: Since writing the above I have learned, thanks to a better method which I have recently adopted for preserving the nests for examination, that sometimes the lower door, instead of being free within the tube and only attached to the lining by the hinge, is surrounded on either side by a delicate silk web, which extends from either edge of its lower surface to the silk walls of the tube below and forms a sort of double gusset. This admits of the movement of the lower door in the way described above, but perhaps serves, together with the solid appendage at the extremity of the free end of the door (that away from the hinge), to prevent the door from being driven too far in an upward direction and thus becoming so tightly jammed as to make the spider a prisoner in her own nest. I think it possible that the lower door is always attached to the tube in this way, but, as it parts readily from the silk on either side when the earth which supports the tube is removed, it very frequently appears to be free, as I have represented it in Plates IX., X., and XI.]