GSO On Aquatic Carnivorous Coleoptera or Dytiscidce. 



vertice nigro-signato, thorace anterius et posterius in medio nigro, elytris 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. 



Fern., elytris in medio partis basalis punctis subtilibus impi-essis. 



In the male of this species the three larger of the palettes on the front feet 

 difier 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 epipleurye 

 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). 9GG. 



1063. Hydaticus vaviegatus, Lap., M.C. — Convexiusculus, latiusculus, lajvigatus, 

 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. 13;, lat. 8 m.m. 



Fern., nitida, elytris ad basin lineolis brevibus numerosis impressis, prothorace 

 litrinque 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, Eio Sappo., 21. 11. 1874, from water standing in a canop, Dr. 

 Trail). 967. 



