Supplement to Harvesting Ants and Trap-Door Spiders

by John Traherne Moggridge; Octavius Pickard-Cambridge

The palpi are long and rather slender, measuring rather over six lines in length; they are similar in colour to the legs, and excepting a few—from twelve to fourteen—short strong spines on the upper side of the extremity of the digital joint, furnished with hairs only. The cubital joint is more than half the length of the radial; this latter is equal in length to the humeral joint, and nearly as long as the femora of the first pair of legs. The digital joint is short, of an oblong oval form, broadest at its extremity. The palpal organs consist of a nearly spherical corneous lobe, prolonged at its fore extremity into a long, slender, tapering, beak-like spine, curving upwards (i.e., with its point near to the radial joint), and inwards.

A broad, conspicuous, shining, corneous band, of a deeper red-brown than the rest, runs round the middle (or equatorial line) of the spherical portion of these organs, covering the greater part of their surface.

The falces are of moderate length and strength, and of ordinary form. They are similar in colour to the legs, and furnished in front, chiefly on their inner edges, with hairs, and at their extremities on the inner sides, with a few, but not very strong nor conspicuous, short spines; their under side (along which the fang lies) is toothed on the inner edge only; the fang is strong and curved, but presents nothing remarkable in form, nor could I detect either denticulation or serration.

The maxillæ are strong, straight, divergent, with a small prominent point at the inner extremity of each; they are as strong, but not so long, as the basal (coxal) joints of the legs of the first pair, of a yellow-brown colour, furnished with hairs, but with no spines of any sort or size.

The labium is similar in colour to the maxillæ, and somewhat quadrate in shape, rounded at the apex; it is furnished with hairs only.

The sternum is of a sub-pentagonal form, much broader behind than in front; its colour is dull yellowish-brown, and it is furnished with hairs, leaving two largish, bare, round, slightly impressed patches, not far from each other, in a transverse line near the middle.

The abdomen is short-oval in form, and very convex above; it projects a little over the base of the cephalothorax, and its upper side is of a purplish grey-brown hue, mottled with a pale dull whitish-yellow, and furnished sparingly with hairs. The sides and under side are of a uniform dull whitish-yellow. The spinners (four in number) are, as usual, of very unequal size, those of the superior pair longish, strong, three-jointed, and up-turned, the inferior pair short but stout, consisting of one joint only and pretty close together.

The female (as it is conjectured to be) of this species was described, in the work to which the present publication is supplementary, from examples found at Mentone. There is little doubt now but that it is not Ct. fodiens, Walck., but whether or not identical with the male above described is not absolutely certain. I think myself (with Mr. Moggridge, see [p. 195]) that it is so, in spite of some differences in the relative size of the eyes, the toothing of the under side of the falces, and the denticulation of the tarsal claws. With regard to the eyes and falces, I am not inclined to lay special stress upon these differences. It is found that in other groups of spiders whose cephalothorax varies very markedly in development in the two sexes, differences of this nature occur. In the present genus, the male has an almost flat caput, while the female has a strongly elevated one; and with respect to the variation in the tarsal claws, no special weight can be attached to it in the present instance, since these claws are not uniformly denticulated in the different feet of the same individual. Another difference is the absence in the male of sundry small but distinct tooth-like spines at the apex of the labium and the inner corner of the base of the maxillæ; the female is also wanting in regard to the very characteristic transverse indentation which divides the caput of the male into two parts. I can, however, trace in the female the slightest possible corresponding depression, scarcely amounting to an indentation, and placed rather nearer to the junctional thoracic pit.

With regard to the differences between this species and Ct. Sauvagii, Latr. (Ct. fodiens, Walck.), size alone would suffice to distinguish them; two females of the latter now before me measuring 13 lines in length; while the male (Aran. nouv. ou peu connus du Midi de l'Europe, par Eugène Simon, Mém., Liège, 1873) measures 8 lines (17 mm.) and the female rather over 14 lines (30 mm.), the fore-central eyes in the female of Ct. Sauvagii appeared to be smaller than those in Ct. Moggridgii and placed rather farther forwards, but the eyes in both are otherwise remarkably similar both in size and position. The males, however, cannot be confounded inasmuch as, according to M. Simon, no trace of any transverse indentation on the caput exists in Ct. Sauvagii.

The denticulation of the tarsal claws in the females of both species is similar, but M. Simon does not mention this portion of the structure of the male he describes of Ct. Sauvagii.