It seems very improbable, however, that it should be mainly intended as a safety place for the eggs or offspring; at least if this were the case we should not expect to find it, as we do, in the nests of very young spiders (fig. B, [Plate IX.]), which could have no use for it.
The large spider and its nest figured at A and A 3 in [Plate IX.] were taken at Mentone on March 17, 1872, and the following is the technical description of the species, written by Mr. Pickard-Cambridge:—
Nemesia Meridionalis. [Plate IX.]
Syn. Mygale meridionalis (Costa). Fauna del Regno di Napoli, p. 14, Pl. I., figs. 1-4, ad partem.
Female adult, length 11 to 13 lines.
This spider is very nearly allied to N. cæmentaria both in general structure and colours, but it may be distinguished by the more elongate form both of the cephalothorax and abdomen; the colours also of the present species are more distinctly distributed; a well-defined narrow marginal band, irregular on the inside, surrounds the thorax; and the caput has a large curved patch of the same on either side of the ocular area, with a broad tapering band tinged with orange, which runs from immediately behind the eyes to the thoracic junction, where it ends in a point. The transverse diameter of the ocular area is also less in proportion to its longitudinal diameter than in N. cæmentaria, and the eyes are all smaller, but placed on a similar oval eminence, and several bristles are directed forwards from the middle of the lower margin of the clypeus, while one or two others are found in the ocular area, and three or four more (long, strong, and nearly erect) form a longitudinal row along the middle of the central tapering thoracic band. The Falces are deeply yellow-brown, with two to three elongate oval patches or short longitudinal parallel bands on their upper sides; in their armature the falces are similar to those of N. cæmentaria. The Labium appeared to be less broad in proportion to its height, and the Sternum smaller and of a more oval form than in that species. The Abdomen is similarly marked, though the chocolate-brown markings appeared to be less deep and dense, being more broken up, but still forming several fairly defined, bold, and broad angular bars or chevrons on the upper side. The inferior spinners, though small (like most of the corresponding pair in species of this family), are yet considerably stronger than in N. cæmentaria.
Adult females of this spider were found in tubular silk-lined holes in the earth, closed at the external orifice with a flat scale-like hinged lid, covered with lichens and mosses. Not quite half way down this tube is a tubular branch running off upwards at an angle of 45° or less; the main tube also at this point is furnished with an elliptical-hinged valve, with which the spider appears to have the power to close the entrance to the branch or to shut off the upper part of the main tube. This branch (found also in the tubes of very young examples) seems to be certainly a strong distinguishing character in the economy of the species, and separates it at once from N. cæmentaria. In the nest of N. meridionalis the tube also projects at times above the surface of the soil upwards among the herbage which serves to conceal it. Costa appears to have had before him this latter species as well as what is here taken as the typical N. meridionalis, as he speaks of the nests under his observation as being frequently branched, while his description would suit both species; his figure, however, more nearly agrees in the thoracic pattern with the spider above described. Ausserer, in his elaborate paper on the Mygalides, lately published (Beiträge &c. vide supra), appears to have overlooked M. meridionalis (Costa) altogether; while Canestrini and Pavesi (Catal. degli Araneidi italiani in Atti Soc. Ital. Sc. Nat. xi. (1869)), p. 25, include it under the synonyms of M. fodiens Walck., from which it is undoubtedly distinct, as may be seen at once, even if it were only by the difference in the form and structure of the lid with which the external orifice of the tubular nest is closed.
In the case of the upper door of these branched nests, as there is but a very thin coating of earth on their upper surface, it is rare to find any of the larger mosses or lichens growing upon them; but, as if to compensate for this deficiency, a variety of foreign materials are employed which are scarcely ever found in cork doors, such as dead leaves, bits of stick, roots, straw of grasses, &c., and I have even seen freshly-cut green leaves, apparently gathered for the purpose, spun into a door which had recently been constructed.
But here again there is the widest possible difference between nest and nest in the degree of perfection in their concealment; and, although as a rule the surface of the upper door harmonizes well with the general appearance of its surroundings, there are some individual nests in which it readily catches the eye and even attracts attention.
Thus, I have seen nests in mossy banks where the doors, being made of nothing but earth and silk, showed distinctly as brown patches against the green; and those doors which are covered with earth only, even when they are surrounded by earth, are often easily detected, because when they dry up, as they quickly do, they become much paler in colour than the earth of the bank, which retains its moisture.