72,6 On Aquatic Carnivorous Coltoptera or Dytiscldce. 



The male has the front tarsi rather large, attaining about 83 m.m. in the 

 transverse direction, and their pubescent area is correspondingly large ; on the 

 intermediate tarsi the basal joint has a linear patch of rather short sexual 

 pubescence ; the female is without sexual sculpture, or trace of rudimentary claw on 

 the hind tarsus. 



This species is excessively similar to C. immarginatus, but is comparatively a 

 httle narrower in form, the male has the front tarsi better developed, and the 

 sexual pubescence of the intermediate feet much less : the epipleurse in their 

 terminal portion are broader and flatter, and on the upper surface the elytra have 

 a slight explanation at the lateral margin before the extremity. 



Tlie species is much larger and more elongate than C. operosus, and the male 

 front tarsi are twice as large, and the intermediate feet with quite different sexual 

 pubescence. 



From C. modestus, this species is distinguished by its more convex form and 

 rather larger size, the larger front male tarsi, and the narrow patch of sexual 

 pubescence on the intermediate feet, and also by the explanation of the elytra just 

 within the lateral margin in their posterior portion ; the species has a very slight 

 tendency to show a metallic lustre on the upper surface. 



A female from Damara land in my collection is perhaps a variety, it has a 

 very slight sexual sculpture on the thorax towards the sides, the epipleuraj are 

 slightly broader, and on one of the hind tarsi there is a very slight rudiment of a 

 supplementary claw. 



Tropical Africa, (Senegal). 1068. 



1139. Cybister dehaani, Aube, Trogusdchaani, M.C. — Parvus, ovalis, convexus, 

 supra nigro-olivaceus, subtus niger, antennis pedibusque anterioribus et inter- 

 mediis rufescentibus, pedibus postei'ioribus nigro-piceis ; elytrorum epipleuris 

 capiteque anterius plus minusve vage rufescentibus. Long, loi, lat. 7h m.m. 



In the male of this species the front tarsi are small, and their pubescent area is 

 absent ; the basal fringing hairs appear at first sight to be absent, but on careful 

 examination they are seen to exist, although very short, and they are placed not 

 quite at the hind margin, but I'un across the basal joint just behind the palettes, so 

 that there is behind them a short glabrous space or heel to the tarsus ; on the 

 intermediate tarsus there are some longf hairs on the underside of the three basal 

 joints, those on the third joint being, however, but very few in number, and 

 considerably shorter than those on the preceeding joints. The female has no 

 sexual sculpture, and no trace of a supplementary claw on the hind tarsus. 



The species is very distinct by its small size from any other as yet known. 



Slam and Cambodia. 1070. 



