726 On Aquatic Curnworous Coleoptera or Dytiscide. 
The male has the front tarsi rather large, attaining about 3} 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 
little narrower in form, the male has the front tarsi better developed, and the 
sexual spubescence of the intermediate feet much less: the epipleuree 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. 
The 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 epipleure are 
slightly broader, and on one of the hind tarsi there isa very slight rudiment of a 
supplementary claw. 
Tropical Africa, (Senegal). 1068. 
1139. Cybister dehaani, Aube, Trogus dehaan?, M.C_—Parvus, ovalis, convexus, 
supra nigro-olivaceus, subtus niger, antennis pedibusque anterioribus et inter- 
mediis rufescentibus, pedibus posterioribus nigro-piceis; elytrorum  epipleuris 
capiteque anterius plus minusve vage rufescentibus. Long, 133, lat. 7$ 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 run 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 long 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. 
Siam and Cambodia. 1070. 
