OCR Text |
Show 1879.] SPIDERS FROM NEW ZEALAND. 687 included in the family Agelenides, where it would appear to come somewhere before the genus Argyroneta. It is allied to Desis, Walck.; but the eyes differ both in relative size and position, the legs are more slender, and the maxillae are not divergent. These differences seem to m e to separate it decidedly from that genus. Dr. L. Koch (Die Arachn. Austr. pp. 345-351, pi. xxix. figs. 1, 2) describes two Australian Spiders which he places in the genus Desis, Walck. One of these (Desis mertensii) appears to be aquatic in its habits, very much like the Spider here described, and to which it bears considerable general resemblance. I have mentioned above some reasons for considering that the present Spider is not a Desis; and for similar reasons I do not think it belongs to the same genus as the Spiders described by Dr. Koch-more especially as in Dr. Koch's two species there are spines on the femora, tibiae, metatarsi, and tarsi of the third and fourth pairs of legs, as well as on the femora of the first and second pairs, whereas in the present Spider there are a very few short spines on the metatarsi and tarsi only of the third and fourth pairs. ROBSONIA MARINA. (Plate LII. fig. 4.) Argyroneta marina, Hector, Trans. & Proc. N . Zeal. Instit. x. p. 300 (1877), and C. H. Robson, I. c. p. 299. Robsonia submarina, Cambr. M S . 1877. Adult male, length, exclusive of the falces, from 4 to 4 | lines; adult female, rather over 6 lines. The cephalothorax and falces are of a dark reddish yellow-brown colour; the normal grooves and indentations very slightly defined. The maxillee, labium, and sternum are of a rather lighter hue than the falces. The legs are pale dull brownish-yellow, the two basal joints nearly as dark as the sternum. The palpi are rather long, slender, furnished with hairs only, and similar in colour to the legs; those of the male bear a very strong general resemblance to those of Drassus lapidicolens, Walck. The humeral joint is curved, the cubital and radial joints together equalling it in length ; the radial is more than double the length of the cubital joint, and has at its fore extremity on the outer side a broadish, but not very long, bifid apophysis, whose lower limb is broad, obtuse, and much larger than the upper; the latter, as well as the superior margin of the former, are of a deep blackish colour. The digital joint is long, narrow, and tapers to a blunt point at its anterior extremity, where there are several short spines. The palpal organs are simple in structure, and not very prominent. The abdomen is of a pale dull yellowish-brown colour, tinged (when alive) with greenish, and pretty well clothed with fine hairs of a darker hue. The falces are porrected almost straight forwards, and are equal in length to that of the cephalothorax. The female resembles the male in colours and general structure, but is larger, and" the falces are slightly shorter. The legs also are shorter, particularly those of the first pair. |