1902.] SPIDERS FROM BORXEO AXD SIXCAPORE, 277 



the base. Elytra very closely rugulose - punctate, gradually 

 widening from the base backwards, bi-oadly rounded and slightly 

 sinuate at the apex, with a short spine on each at the suture. 



NOTHOPEUS INTERMEDIUS, sp. n. (Plate XIX. fig. 21, (5 .) 



Corpore supra, cajnie toto, pedihiis antennisque fulvis, his verstis 

 cipicem infuscatis ; thorace siibtus et abdomine nigro-cyaneis, 

 sed prosterno inesost&rnoqiie medio, maculis duabus metasterni 

 et segviejito primo abdominis fulvis, hoc arge'nteo-sericeo ; 

 elytris (quod attinet ad hoc genus) perelongatis, apicem, 

 abdominis fere attingentibus. 



Long. 27 ; lat. (pone humeros) 7 mm. 



Hah. Sarawak, Mt. Penrissen, May 1899. One male example; 

 in the Sarawak Museum, Kuching. 



Head, antennae (except the last four joints, which are brownish), 

 disk of pi'othoi'ax, and elytra tawny red ; body underneath bluish 

 black, but with the prosternum, mesosternum, a spot on each side 

 of the metasternum, and the whole of the first abdominal seg- 

 ment tawny, the latter being covered with a silky pubescence 

 giving silvery reflexions in certain lights. The elytra, though 

 unusually long for this genus, extending nearly to the apex of 

 the abdomen, are considerably narrowed from a little behind the 

 shoulders, and each in its posterior half is scarcely half as broad 

 as it is at the base. The hind tibite of the male are thickened 

 and subcylindi'ical, nai'roAved towards the base and very slightly 

 also towards the distal end. 



This species comes nearest in structural characters to Aphro- 

 disinvi tibiale Kits., from Assam, but difiei-s from it in having 

 the elytra still more attenuated behind and the front of the head 

 narrower. Ritsema placed his species in Aphrodisium as an 

 aberrant member of that genus ; but considering the reduction 

 in the size of the elytra and the peculiar form of the male hind 

 tibise, I believe it to be better placed in Ifothopeus, though 

 undoubtedly showing strong afiinities with Ajyhrodisium. His 

 species and the one here described are both extremely interesting 

 as showing the gradual progress of that modification leading to 

 the very shortened elytra and the strongly mimetic forms cliarac- 

 teristic of the genus Nothopeus. 



PsEBEXA, gen. nov. 



Head short, as broad as the prothoi'ax ; eyes finely facetted, 

 deeply emarginate, Avith the lower lobes rounded, the upper A^ery 

 narrow ; palpi short and slender. Antenn£e (?) a little longer 

 than the body, slender, filiform ; 3rd, 4th, and 5th joints siib- 

 equal to one another, each twice as long as the 1st ; 6th distinctly 

 shorter than the 5th ; the succeeding joints gradually dimin- 

 ishing in length. Prothorax subcylindrical, as broad as it is 

 long. Elytra short, squamiform, not reaching beyond the apex 

 of the first abdominal sternite. Prosternum narrowed behind ; 

 front coxfe prominent, their a,cetabula angulate outwards and 



