732 On Aquatic Carnivorous Coleoptera or DytiscidoB. 



basal portion of the wing-cases a fine sexual sculpture consisting of very short 

 isolated scratches. 



The species differs from C. asiaticus, by its form which is broader in front and 

 more convex, the colour of the undersurface is darker and the female has a fine 

 sexual sculpture. The hook-like dilatation near the termination of the elytra is 

 less distinct, and the terminal portion of the band is less deBnite : the epistome is 

 nearly entirely yellow, but there is generally a little descent of the dark colour in 

 the middle so as to diminish there the length of the yellow mark. 



It also resembles excessively the Javanese varieties of D. tripunctatus, but is 

 smaller, has a pale patch on the sides of the breast ; and the patches of pubescence 

 on the intermediate male tarsi are narrower, and extend on to the third joint. 



Siam, and interior of Malay peninsula, Castlenau. 1074. 



1144. Cybister lewisianus. Sharp, Tr. Ent. Soc. Lond. 1873, p. 46. — Ovalis, 

 convexus, anterius evidenter angustatus, supra olivaceo-niger, capite anterius 

 prothoracisque lateribus testaceis, elytris margine externo (cum epipleuris) sat late 

 testaceo ; corpore subtus testaceo, ad latera anguste nigricante, pectore in medio 

 plus minusve infuscato ; pedibus quatuor anterioribus testaceis, tarsis intermediis 

 piceis ; pedibus posterioribus femoribus rufis, tibiis tarsisque nigricantibus ; 

 elytrorum epipleuris versus apicem distincte latioribus et planatis ; processubus 

 co.xalibus apice conjunctim fere truncatis. Long. 25, lat. 14 m.m. 



The male anterior tarsi are small, but do not differ much from those of 

 D. tripunctatus ; the intermediate feet appear at first entirely destitute of sexual 

 pubescence, but on careful examination there is seen a narrow line of very short 

 hairs on the first two joints. The female has no sexual sculpture. 



Although very similar to C. asiaticus and C. fumatus the species is readily distin- 

 guished by the form of the coxal processes which are soldered together to the 

 apex so that there is scarcely any notch between them : the epipleurae before 

 their termination are also slightly, but undoubtedly, broader than in the allied 

 species. 



The specimens from China are larger and broader than those from Japan, and the 

 colour of the undersurface is darker in the middle. 



Japan, China, (Shanghai, Felder and Abbe David), Assam. 1075. 



1145. Cybister senegalensis, Aub^, Trogus senegalensis, M.C. — Minor, ovalis, sat 

 convexus, parum latus, supra olivaceo-niger, capite anterius prothoracisque 

 lateribus testaceis, elytris margine externo (cum epipleuris) sat late testaceo ; corpore 

 subtus nigricante, pedibus quatuor anterioribus testaceis, tarsis intermediis 

 pedibusqne posterioribus picescentibus, antennis testaceis. Long. 20, lat. 10 m.ru. 



