688 REV. O. P. CAMBRIDGE ON NEW [Nov. 18, 



Examples of both sexes of this exceedingly interesting Spider were 

 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, iu 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 iu 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 sea 1 . 



Fam. Theridiides. 

 Genus Argyrodes, Linn. 

 Argyrodes lepida, sp. n. (Plate LII. fig. 5.) 



Length of the adult female \\ hue. 



Cephalothorax oval, truncated in front ; lateral marginal constric- 

 tions at caput very slight ; the profile line forms a regular and con- 

 tinuous 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 

 Dcsis robsoni (Trans. & Proc. N.-Zeal. Instit. vol. xi. p. 263, pi. xii., 1879). Dr. 

 Powell considers that it is a Dcsis, and identical in genus with the Spiders de- 

 scribed (Die Arachn. Austr. I. 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. supri). 



