OCR Text |
Show 336 REV. O. P. CAMBRIDGE ON SPIDERS [Apr. 20, ARGYRODES ULTJLANS, sp. n. (Plate XXX. fig. 14.) Adult male, length from the fore extremity of the caput to the spinners 14; line, and to the apex of the abdomen 2\ lines ; the corresponding measurements of the adult female are 2 and 4 lines. The cephalothorax, legs, palpi, and falces are of a deep yellowish-brown colour. The legs are rather the palest, they are long and slender, 1, 2, 4, 3, and furnished with fine hairs. The fore part of the caput is divided into two lobes, like many others of the genus ; but the form of the lobes is very distinct from that of any other species, and very characteristic. The inferior lobe is very strong, obtuse, and, looked at in profile, projects a little beyond the upper one, which is much smaller and transversely impressed just in front of the fore central pair of eyes. These lobes are, like the corresponding ones in other species, clothed with hairs, which are directed over the intervening cleft. The abdomen is greatly produced backwards, tapering to a blunt conical point; its length from the spinners to the apex is nearly or quite double that from the spinners to the cephalothorax. It is of a dull sooty-black hue, deepening to the apex; the upper part is bordered on each side by a broad longitudinal silvery band, which does not, however, nearly reach the apex; and close behind the spinners, underneath, are two silvery spots in a transverse line. The palpi are moderately long ; the radial and cubital joints are rather short, and of very nearly equal length ; the digital joint is large, oval, and devoid of the strong process near the extremity characteristic of that of Argyrodes epeira, Sim., and several others. The palpal organs are compact and moderately complex, but do not present any very conspicuously prominent processes. The female is larger, and its abdomen stouter ; but in colours and markings the sexes are remarkably alike. Examples of this species were contained in Prof. Traill's Amazons collection. ARGYRODES MINAX, sp. n. (Plate XXIX. figs. 15, c, d, e, 15 a, 15 5.) Adult male, length to the spinners 1\ line, and to the apex of the abdomen 2 lines. In the form of the caput this Spider is very like the next species (Argyrodes afiinis, Cambr.). In both Spiders the clypeus is prominent, and divided by a distinct transverse cleft, almost amounting to a simple perforation, so nearly do the adjacent margins of the two segments meet. The present Spider, however, may be distinguished at once by the greater and more gradual rise of the caput from the thoracic region, and by the cleft above mentioned dividing the clypeus into two equal parts, whereas in A. affinis it is placed close beneath the fore central eyes (Plate X X X . fig. 16 b). A _ comparison of the figures given of the two Spiders will render this apparent at a glance. |