18/9.] SPIDERS FROM NEW ZEALAND. 687 



included in the family Agelenides, where it would appear to come 

 somewhere before the genus Argxjroneta. 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 dif- 

 ferences seem to me 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, /. c. p. 299. 



Robsonia submarina, Cambr. MS. 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 maxillae, 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. 



