572 On Aqua'ic Carnivorous Coleoptera or Di/(isciJce. 



IS equidistant from the suture and the second stria, while the outer one is three 

 times farther from the lateral margin than it is from the third stria. The male has 

 the front and middle tai-si broadly dilated, the front tibiae much bent at the base, 

 and very distinctly notched at some little distance below the knee. 



Amazons ; found by Professor Trail in the water standing in the bottom of a canoe in the Rio Sappo, 

 21st. Nov, liS74. 050. 



833. Copelatus til)iali.s, n. sp. — Oblongus, elongatus, angustulus, fere parallelus, 

 capite, prothoracis lateribus, elytrorum basi, antennis pedibusque rufis, prothorace 

 medio elytrisquo vitta sublaterali rufescentibus ; prothorace fere Itevigato ; elyti'is 

 striis quatuor sat profundis ; antennis subelongatis. Long. 5 s-, lat. 2^ m.m. 



In tlie male the front and middle tarsi are broadly dilated, and the front tibise 

 are so abruptly bent near the base as almost to appear angulate, and they have a 

 very distinct notch on the inner face below the knee ; the female I do not know. The 

 species is closely allied to Copelatus prolixus, but is much less elongate, and has 

 numerous minor points of distinction ; the disposition of the striae on the elytra is 

 about the same in the two species, but in the present one they are deeper, and the 

 sutural stria seems rather shorter. 



youth America, (Brazil.) 051. 



834. Copelatus nitidus, n. sp. — Oblongus, sat elongatus et angustus, minus depres- 

 sus, nitidior, niger, elytris castaneis, antennis pedibusque rufis ; prothorace parce 

 punctulato ; elytris striis quatuor sat profundis, prima (a sutura hand remota) quam 

 ceteris paulo longiore. Long. 5h, lat. 2| m.m. 



In the male the front and middle tarsi are moderately dilated, and the front tibia; 

 are nearly simple; the female I do not know. The only individual I have seen is 

 in very bad condition, but the species is a clearly distinct one, the hind co.xpe being 

 shorter and rather different in form from the rest of its allies. In the collection of 

 the Brussels Museum there is a specimen which is probably the female of this 

 species, but it is considerably smaller, and has the strioe of the elytra finer. 



Soutli America (Columbia, coll. de Bonvouloir). 6.52. 



835. Copelatus guerini, Aube, M.C.— Oblongus, sat angustus, fusco-castaneus, 

 capite, prothoracis lateribus olytrorunique basi rufescentibus ; antennis pedibusque 

 rufis; prothorace obsoletius punctato ; elytris parce obsolete piinctulatis, striis 

 quatuor elongatis, prima a sutura remota. Long. o«, lat. 3 m.m. 



In the male the front and middle tarsi are a good deal dilated, the front tibiaj 

 are bent below the knee, and their basal part is slender, and is broadlj' and indis- 

 tinctly eraarginate below the knee. I have seen only one specimen, in bad condition ; 



