1880.] OF THE GENUS ARGYRODES, 32.') 



extremity on the upperside it is bisected by a tapering black stripe, 

 whicb ends at the apex of the cone ; in the males this stripe is 

 merely a short black line from which one or two vein-like branches 

 issue obliquely on each side. The underside is black, or else black- 

 brown deepening into black on each side ; the margins of this black 

 portion are well defined, dentated, and extend a little way up the 

 sides. The dentation of the margins differs in the sexes, as will be 

 seen from the figures given ; in about a dozen examples of the 

 female but very slight variation was apparent in the character of this 

 dentation in that sex. On each side underneath, a little way in front of 

 the spinners, are two round, shining, silvery spots in a transverse line. 



The palpi of the male are in general appearance very like those of 

 A. epeircB, Sim., and others ; the cubital joints are tumid and cla- 

 vate, the radials short and spreading ; the digitals are large, with a 

 strong prominence or lobe towards their extremity on the inner side. 

 The palpal organs are moderately complex ; and at their fore ex- 

 tremity is a rather prominent process, whose termination is bifid or 

 distinctly cleft. 



An adult male and females of this Spider were contained in a col- 

 lection of Spiders made in the Amazons of South America by Pro- 

 fessor Traill, to whose kindness I am indebted for them. I have 

 but little doubt that it is the Spider described by Prof. Taczanowski, 

 /. c. supra. 



In the form of the caput Argyrodes nephila is very similar to 

 A. rostrata, Bl. (Seychelle Islands) ; the anterior lobe of this latter 

 species, however, is stouter, and the eyes of the hind-central pair are 

 nearer to the summit of the occiput {vide Plate XXVIII. fig. 4 a). 

 The abdomen also is of quite a different form — less elevated, very 

 obtuse at the apex, and with a distinct pattern on the sides (fig. 4 6'), 

 this part in A, nephilce being immaculate. 



Argyrodes argentata, sp. n. (Plate XXVIII. fig. 5.) 



Adult male, length jJy of an inch ; female considerably larger. 



This Spider is very closely alHed to Argyrodes nephilee, Tacz., 

 resembling it in general form, colours, markings, and appearance. 

 It is, however, considerably larger ; the form of the caput differs in 

 the more curved shape of its anterior segment, which is also rather 

 longer in proportion to the posterior one ; the hind central pair of 

 eyes are also placed further up on the occipital part of the posterior 

 segment, being thus considerably removed from a straight line with 

 the lateral pair and fore-central eye on each side. 



The abdomen also is less elevated, and its conical point more ob- 

 tuse ; it is of a similar brilliant silvery hue ; its upper point slightly 

 tipped with brown, and a slender longitudinal central black or deep- 

 brown line on the upperside, sometimes enlarged in an angular form 

 at one or two points, from each of which issues a short vein-like line. 

 The central line or stripe seldom appears to reach the conical point 

 of the abdomen, and does not differ in form or strength in the sexes. 



The legs are long, but not excessively so ; and their relative length 

 is 1, 2, 4, 3 ; they are of a pale yellow colour, slightly tinged with 



