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Show 770 REV. O. P. CAMBRIDGE ON N E W ARANEIDEA. [June 21, In the absence of spines on the legs there is a close approach to Theridion, Walck., while in their relative length they are like Linyphia, Latr. Although the development of the caput is so strong, yet in the adult it would be probably found to be of a still stronger and more extraordinary nature. Gen. ARIAMNES, Thor. (Ariadne, Dol.). ARIAMNES ATTENUATA, sp. n. (Plate LXVI. fig. 3.) Adult male, length 8 lines ; length of cephalothorax f line ; length of spinners If line ; length of abdomen 64 lines. The whole of the fore part of this Spider, including the legs and palpi, is of a dull yellow-brown colour. The abdomen is of a still duller hue, thinly mottled (chiefly on the sides) with small yellowish silvery spots. The cephalothorax is of a rather flattened oblong form, the caput being a little drawn out and elevated at its fore extremity, ending in a short, somewhat conical point in the middle of the ocular area, which is furnished with strong hairs; some of these form a somewhat horn-like tuft and are curved forwards, meeting others curved in an opposite direction. The eyes are unequal in size; those of the fore and hind central pairs (the first being the largest) form a large square surrounding the conical eminence of the caput ; the lateral pairs are rather close to the others on either side; those of each lateral pair being contiguous to each other. The legs are long, very unequal in length, 1, 4, 2, 3, slender, furnished with very short fine hairs only. The palpi are long ; the cubital joint curved, clavate, and longer than the radial, which is also curved, and enlarged gradually to its fore extremity ; the digital joint is large, of au oblong-oval form, somewhat split or bifid at its fore extremity. The palpal organs are complex, composed of variously formed corneous processes, but all tolerably compact. The falces are rather small and weak, straight, and nearly vertical. The maxilla are strong, especially at their base, inclined towards the labium, and obliquely truncated at the extremity on their outer sides. Labium short, of a somewhat subtriangular form, and its junction with the sternum scarcely perceptible. Sternum large, of an elongate triangular shape, strongly hollowed or indented between the insertions of the legs. Abdomen narrow, and drawn out at its hinder extremity in an exceedingly long tapering cylindrical form, terminating gradually in a fine sharp point. The spinners are compact, and placed beneath the abdomen at a distance from the cephalothorax rather exceeding the length of the latter ; the produced portion of the abdomen is more than seven times the length of the rest, i. e. from the spinners to the cephalothorax. The abdomen is furnished with hairs, which become longer, coarser, and more abundant towards the hinder extremity. |