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Show 688 REV. o. p. C A M B R I D G E O N N E W [Nov. 18, Examples of both sexes of this exceedingly interesting Spider kindly sent to me in 1877 by Capt. F. W . Hutton, having been captured by Mr. C. H. Robson in tidal pools at Cape Campbell, in New Zealand. On a careful examination, it appeared to me that a new genus must be established to receive it. I therefore prepared a description of it under the name Robsonia submarina, dedicating the genus to its finder, and conferring its specific name on account of its submarine habits. Subsequently I find that Mr. Robson has published (I. c. cit. supra) an account of this Spider; and Dr. Hector (the Editor of ' Tr. N. Z. Inst.') has, in a footnote to Mr. Robson's paper, proposed for it the specific name marina, including it in the genus Argyroneta. The habits of this Spider are so abnormal, that I cannot refrain from giving almost verbatim the following extracts from Mr. Rob-son's very graphic account:- " This Spider is found in the tidal pools at Cape Campbell, and is quite at home under water, forming its nest in an old Lithodomus-hole, of which the rocks are full. All the Spiders of this kind which we have found have had nests in these holes, and always under water at all times of the tide. Over the mouth of the hole the Spider spins a close web, which, when finished, looks like a thin film of isinglass, and is water-proof; behind this film is the nest and egg-sac, which last is of various shapes and contains a large number of eggs. When the Spider is disturbed, it goes to the bottom of the pool; and if a small stick or straw is extended to it, it at once gets ready for a fight, advancing its long and powerful falces for that purpose. When a small fish is placed in a bottle of water with one of these Spiders, the latter will attack it at once, driving its long sharp fangs into the fish near the head, and killing it instantly." Excepting in its aquatic habits, concerning which, however, more detail is very desirable, there is but very slight affinity between this Spider and Arygroneta aquatica. It is the first instance, however, on record of a Spider inhabiting the sea1. Fam. THERIDIIDES. Genus ARGYRODES, Linn. ARGYRODES LEPIDA, sp. n. (Plate LII. fig. 5.) Length of the adult female 1^ line. Cephalothorax oval, truncated in front; lateral marginal constrictions at caput very slight; the profile line forms a regular and continuous curve, only interrupted by a slight notch immediately behind the eyes. The ocular area is a little prominent at its fore part, and the height of the clypeus is nearly about equal to half that of the 1 Since the above description was written, I have received Dr. Llewellyn Powell's paper on this Spider, which is there described under the name of Desis robsoni (Trans. & Proc. N.-Zeal. Instit. vol. xi. p. 263, pi. xii., 1879). Dr. Powell considers that it is a Desis, and identical in genus with the Spiders described (Die Arachn. Austr. 1. c.) by Dr. L. Koch. I still doubt this, for the reasons given above. There appears, however, to be no reason to supersede the • specific name given to this Spider by Dr. Hector (I. c. supra). |