Nemesia (Mygale) meridionalis, Costa.[97]
[97] Costa, Fauna del Regno di Napoli, Aracnidi (1861), p. 14, tab. i. figs. 1-4. [Translation.]
"M. fusco rufoque-flavicante, maculis obscurioribus, thorace radiatim, abdomine seriatim dispositis, subtus thorace rufescente, abdomine flavidulo, mandibulis spinarum serie unica, tarsis omnibus spinulosis."
"The cephalothorax oval, elongated and truncate in front, while the head is smooth and bare, with a group of eight eyes, a little keeled in the middle; of a fulvous-brown colour, with ten rather dusky spots arranged in rays, and corresponding to the direction of the eight legs (anche) and the two maxillæ. The mandibles are large, horizontal at first, then curved downwards, making a quarter of a circle, furnished with numerous hairs, especially on the inner side, and at the anterior extremity above there are mobile and rather long spines; below they are channelled, with six little teeth or spines on the edge (rilievo) of the inner face, clothed with many bristling hairs, with which the outside is also covered, but without any teeth; on the inner face they are flattened, so that they fit perfectly close. The fang is strong, curved, acute, and black. The maxillæ are clothed with brown hairs almost as the legs are, and at their extremity, on the outer side, stand the long palpi, rather hairy (pelacciuti), terminated by a very short and simple little claw. The sternal lip is very small and round. The abdomen oval, longer or shorter according to age, dusky ash in colour, spotted with brown, and covered with short and depressed (rasicci) hairs. The brown spots are disposed in slanting lines, placed obliquely to the median line, which is also brown; below it is somewhat lighter, and becomes slightly yellow, increasingly so in the female as pregnancy advances. The pulmonal sacs are always pale yellow, and involved in the fold (tramezzati dalla ripiegatura). Between these, and within the fold itself, the female sexual organ opens, consisting of a transverse opening invisible to the naked eye, but clearly seen on using a lens and removing the fold under which it is concealed, by means of the point of a scalpel or of a pin. The posterior extremity of the anus presents four spinnerets, of which the two upper are much the longer, and composed of four easily seen joints, the lower very short. The feet are moderate, and the longest are of the length of the entire body when this is fully developed (quando è perfettamente sviluppato); of these the fourth pair are about a third longer than the first, the third of about the same length as the second, which is the shortest of all. The tarsi of these are armed with two small curved claws, and the third and fourth joint with many long, delicate, straight, and mobile spines, which in the first pair become fewer as they approach the last joint. The eyes are arranged in three lines, as they are represented in C, [Plate I.], Fig. 3, and of these the two last of the posterior line are white and glistening, the others brown.
"Our Mygale lives in tubular cavities, or burrows, which she excavates for herself in loose and friable soil, in walls made of volcanic earth, in shady places, and for the most part turned to the north or to the west, seldom to the south—hence cool and rather damp. The burrows do not exceed the length of a palm, eight lines at their widest part. For about the length of an inch the tube is funnel shaped, thence it continues of a nearly uniform magnitude. Its first direction is almost horizontal, then it rises continually, turning to the right or left, and sometimes makes zigzags. As the tubes are excavated in friable soil, she takes care to tapestry them inside with the same glutinous material of which the other races make their web, by means of which the burrows are made smooth on the inside, and to strengthen them in such a manner that even when the outer earthy part has become cracked, or been torn away by the action of the rain, they remain firm and fit to conceal their inhabitant. I have often found the tubes of web thus left exposed, as they are represented in [Plate I.], Fig. 4, situated in the cement of a wall, and among Lycopodium denticulatum, Adiantum Capillus-Veneris, Marchantia polymorpha, and other small plants. And it seems that the animal, perceiving the nature of the soil, takes care to reinforce the silken case, so much the more as she finds the earth less firm, and vice versâ. So that in burrows excavated in solid ground, with the exception of a little space close to the aperture, the nest is merely smoothed and daubed; while sometimes the spider constructs a tube so strong that it supports itself even when deprived of all the earth, the animal having had the foresight to attach it along the course of the clefts of the rock, or to the cement of the pieces of tufa in the wall, as represented in [Plate I.] They have often also a double aperture, and the upper portions of the burrows converging, meet and anastomose at about two inches distance. The aperture is closed by a little door or valve (a), which, having its hinge in the upper part and a little on one side, falls by its own weight, and fits itself exactly to the opening. The outer surface of the wicket is covered with earth, cemented by the glue of the spider, so that it is rendered imperceptible to common eyes, and the industrious little creature takes care to leave around the aperture a kind of rim, to which the door fitting closely, leaves no passage for any animal, nor does it show its edges. At the bottom of its tube the creature keeps her numerous offspring, and always stands herself as sentinel at the door, holding the wicket raised by means of the four anterior feet, and the palpi, curved extremities of which she inserts between the rim of the tube and of the door, as represented in a' f. Sometimes, however, they do not appear, but she leaves only the chink for observation, as one sees in a of the same figure. Fig. 2, at c, represents the aperture of an abandoned burrow, and at d the raised door of another burrow, with its almost funnel-shaped aperture. That which Sauvage, Olivier, and Latreille relate of her is not true—namely, that she remains at the bottom of the burrow, and runs to the door only when she sees it threatened, in order to keep the door firmly closed. On the contrary, always standing at the door as sentinel, she leaves it as soon as she thinks it in danger, so that it can be raised without the least effort: but if you hold it a little raised without making any sign of movement, she turns on her back, and comes out to draw it down with her feet, making all the efforts she can to conquer the obstacle. But if you take it away entirely, she turns down the edges to close the aperture as best she can, and that she does hurriedly, without waiting for night. The light seems to offend her so much that, if exposed to the full day, she remains so stupefied as to appear dead, nor does she move even if shaken; on the contrary, she constantly stops still and holds herself with her feet pressed against her body. At last, if very much disturbed, she runs quickly for some distance, till she finds a place in which to hide her head, and from thence she does not stir. I have observed that the burrows are always short when the aperture is small, and increase in length as they augment in diameter, which makes me conclude that it is not true that they begin their excavations from the base of the mother's tube, where I have never found any communication with others. This spider is found in the neighbourhood of Naples (ne' contorni della Capitale), on the Camaldoli, in the island of Ischia, where it lives near the sources of mineral waters, in Gaeta at the foot of the olive trees, among the stones in the ground, &c. &c.
"Observation. The difference which distinguishes our Mygale from the Sauvagesii consists, first, in the toothing of the mandibles, which is observable on one side only of the channel, and not on both; secondly, in the tarsi all equally armed with spines, and not only the four anterior ones; thirdly, in the colour of the thorax and the abdomen, which is not uniform as is usual in the Sauvagesii. Nevertheless, such differences might be in part climatic, which would cause our Mygale to be considered as a mere variety of the same species, and the others might be the result of the different method of examining the parts, and of the goodness of the instruments."
At p. 19, in the Fauna del Regno di Napoli, M. Costa gives the following account of the nest of Nemesia cellicola, which he discovered above San Martino in September, 1833:—
"Vive entro la polvere arida, nelle cavità oscure delle muraglie, e propriamente nelle così dette Saettiere, ove, col glutine suo, si costruisce un tubo delicato e mobile, che ha cura di affidare nel suo origine a qualche corpo stabile nel fondo del muro, e che in terra nella polvere, aprendosi l'altro estremo sul piano inclinato dalla polvere stessa costituto."
This, with the exception of the words "e che in terra nella polvere," which are unintelligible to me as they stand, and appear to want a verb, may be translated as follows:—