On Aquatic Carnivorous Coleoptera or Dytiscida. TLC 
Group 2. 
1122. Cybister sugillatus, Er., Trogus besignatus, M.C_—Ovalis, parum latus, supra 
olivaceo-niger, prothoracis lateribus plus minusve obsolete rufescentibus, subtus 
niger, pedibus nigris, plus minusve rufo-variis, tibiis posterioribus superne versus 
geniculam plus minusve rufescentibus ; antennis rufis, extrorsum fuscescentibus. 
Long. 22, lat. 12 m.m. 
In the male of this species the front tarsi are comparatively small, and the pub- 
escent area on the undersurface of the basal joint is quite small; the longitudinal 
band of sexual pubescence on the undersurface of the basal joint of the middle tarsi 
is so little developed that it easily escapes detection, and consists only of a few 
short pale setze. ‘The female has no sexual sculpture ; the obsolete supplementary 
claw of its hind foot is easily detected. 
The species varies a good deal in size and in other respects; it is sometimes 
peculiarly dull and its upper surface has then a greasy appearance, at other times 
it is comparatively shining, and may even have a faint metallic tinge. The reddish 
colour at the sides of the thorax can be sometimes scarcely perceived while at other 
times it is very distinct ; there is often a dark red spot near the extremity of each 
wing case, but sometimes it is quite absent: the colour of the legs also varies a 
little : the intermediate and anterior femora are nearly black, but are reddish towards 
their apex, and their trochanters are also red: there is a more or less obscure red- 
dish spot on each side of the basal abdominal segments. Cybister notasicus, Aubé, 
and C, olivaceus, Boh., are pretty certainly merely synonyms of this species, which 
is usually known in collections under the name of C. bisignatus, Aubé. 
China, Thibet, India, Malacca, Philippine Islands, Sumatra. 1053. 
1123. Cybister (Trogus) nigripes, Wehncke, Stet. Ent. Zeit. XX XVII, p. 358.— 
Ovalis, sat latus, parum convexus, niger, elytris posterius subtiliter transversim 
corrugatis, epipleuris posterius sat latis et planatis. Long, 21, lat. 12 m.m. 
I have seen but a single individual of this species, and it is in such very bad 
condition that I cannot exactly determine its characters ; it differs from C. sugillatus, 
by its much broader form, by the corrugate elytra and broader epipleure ; from C. 
siamensis it differs by its much smaller size and shorter form; it has probably the 
same sexual characters as the two species alluded to, and it is probable that the 
black colour of the legs is due to this being dyed by the complete rotting of the 
interior of the specimen. 
Borneo. 1069. 
1124, Cybister siamensis, n. sp.—Ovalis, latus, anterius angustatus, niger, 
pedibus anterioribus et intermediis rufo-variis, antennis rufis extrorsum fuscescenti- 
4Z 2 
