680 On Aquatic Carnivorous Coleoptera or Dytiscide. 
vertice nigro-signato, thorace anterius et posterius in medio nigro, elvtris nigro- 
vermiculatis post medium nigro-fasciatis, post fasciam pallidioribus, pedibus 
anterioribus testaceis, posterioribus rufescentibus, tibiis nigricantibus ; elytrorum 
epipleuris vix latis. Long. 12, lat. 7 m.m. 
Fem., elytris inmedio partis basalis punctis subtilibus impressis. 
In the male of this species the three larger of the palettes on the front feet 
differ but little in size from the others. 
The species is very similar to Acilius circumscriptus, but is broader in front, and 
the black marks on the thorax do not extend so near to the sides ; and the yellow 
colour on the wing-cases bears a larger proportion to the black colour, the epipleurze 
are decidedly broader, and in the female the very fine punctures on the wing-cases 
do not extend so far backwards, and there are none on the thorax. 
I have seen but very few individuals ; they show some variation in the colour 
of the under surface which is sometimes blacker, sometimes redder. 
South America, (Columbia). 966. 
1063. Hydaticus variegatus, Lap., M.C.—Convexiusculus, latiusculus, levigatus, 
nitidissimus, subtus niger, prosterno anterius flavescente, supra nigro testaceoque 
variegatus, capite anterius et ante verticem testaceo, prothorace in medio et ad latera 
testaceo, anterius et posterius nigro, elytris ad basin nigro-variegatis, pone medium 
fasciis irregularibus a fascia lata nigra separatis testaceis, humeris plaga intus a 
plaga nigra limitata testacea ; pedibus anterioribus testaceis, posterioribus plus 
minusve nigricantibus, epipleuris latis. Long. 133, lat. 8 m.m. 
Fem., nitida, elytris ad basin lineolis brevibus numerosis impressis, prothorace 
utrinque sparsim lineolato-punctato. 
In this species the anterior black mark on the thorax is broad, but. does not 
reach the sides, at its termination it emits a prolongation backwards; the hinder 
black mark reaches to the hind angles, but is there very short. The elytra have 
a humeral patch quite yellow, and this patch is limited inwardly by a black mark ; 
the rest of the basal portion of the wing case is black, marked with numerous 
small yellow marks, which become more indistinct on the middle part which is, 
therefore, nearly entirely black, behind this black point is a variable, irregular, 
transverse fascia of yellow, interrupted at the suture, behind this the colour is again 
quite black, while just before the apex there is another very irregular, interrupted 
yellow fascia. 
I have seen very few specimens of this species. 
South America, (Brazil ; Amazons, Rio Sappo., 21. 11. 1874, from water standing in a canoe, Dr. 
Trail). 967. 
