764 MR. A. G. BUTLER ON [DeC. 19, 



This and the following are allied to C. quadrata of Ceylon ; if 

 therefore the latter should be removed from the genus, tbey must 

 go with it. 



2. Chrysso nivipictus, sp. n. (Plate LVII. figs. 1, 1 «.) 



$ . Falces, maxillse, labium, sternum, and legs of a clear pale 

 yellow colour ; the cephalothorax above black, with a lateral (almost 

 marginal) pale yellow stripe oa each side of the thoracic region ; abdo- 

 men above black, spotted with white as follows : — two small dots in 

 the centre of the anterior region, two large transverse oval spots, one 

 on each side behind these, two small spots beyond the middle, fol- 

 lowed immediately by three large almost confluent spots, the central 

 one transverse and with a small spot behind it; ventral surface 

 shining black. 



Cephalothorax slightly broader than long, expanded laterally in a 

 regular arch behind the caput, and depressed at the back ; caput 

 similar in form to that of the preceding species, but the base of the 

 falces rather more strongly indented in front ; the anterior central 

 and lateral eyes are also similar, but the posterior central eyes are 

 smaller ; the central oculiferous area represents a cone, the apex 

 of which is truncated ; between the two central pairs of eyes is a 

 long bristle directed forwards and emitted from behind the eyes ; 

 the lateral margins of the head are sharply carinated and divided by 

 a broad oblique shallow groove from the thoracic region ; the abdo- 

 men is quadrate, diamond-shaped, the lateral and posterior angles 

 acute and spine-like, the dorsal surface very convex, rugose, the 

 stigmata represented by shallow depressions, the ventral surface is 

 keeled ; the legs are slender, cylindrical, sparsely setose, their rela- 

 tive length ], 4, 2, 3. Entire length of body and cephalothorax 

 2| millim. 



One example : Central Madagascar. 



Thwaitesia, O. P, Cambridge. 



This genus was described last year (P. Z. S. 1881, p. 766) for a 

 Cingalese species ; and in this year's 'Proceedings' two additional 

 species from the Amazons were added (see above, pp. 431, 432). 



3. Thwaitesia pulcherrima, sp. n. (Plate LVII. figs. 7, 

 7 a, b.) 



Nearly allied to T. margaritifera^ from which it differs apparently 

 in the form of the abdomen and its somewhat brighter coloration ; 

 the abdomen is ornamented above with a large brown cruciform 

 marking which passes into the lateral articulations. 



5 . The cephalothorax is pale yellow, adult examples having a 

 more or less defined longitudinal dorsal carmine-red band from the 

 oculiferous region backwards ; the eyes are black ; the legs agree in 

 colour with the cephalothorax ; the articulations of the tibise and 

 metatarsi of all the legs are more or less strongly banded with car- 

 mine, a portion of the extremities of the metatarsi being also red, 

 excepting those of the front pair of legs, which are brown : the fine 



