On Aquatic Carnivorous Coleoptera or Dytiscidce, 341 



232. Desrnopachria varians, Wehncke, Stet. Zeit. 1877, p. 151. — Brevis, lata, 

 subrotundata, convexa, testacea, prothorace basi medio elytrisque nigro-signatis ; 

 crebre fortiter punctata, elytris stria suturali impi'essa. Long. 2^, lat. if m.m. 



Closely allied to Desrnopachria suturalis (No. 229), but smaller and differently 

 coloured ; the ground colour is yellow, and the base of the thorax is black, and 

 the elytra are marked along the suture with black, and external to this have some 

 large confluent, longitudinal black marks. This insect at first sight bears a good 

 deal of resemblance to Dytiscus inasquahs, (No. 381), but it is broader and rather 

 less convex, more finely punctured, and has the antennae shorter and finer. 



Brazil, (Bahia). .57. 



233. Desrnopachria laevis, n. sp. — Brevis, lata, subrotundata, pernitida, im- 

 punctata, castaneo-testacea, pectore abdomineque nigris. Long. If, lat. li m.m. 



The head is very broad and short, very gently rounded in front, and very finely 

 margined. The thorax is slightly sinuate on each side near the hind angles, and 

 is quite impunctate. The elytra are also impunctate, as is the under surface. 



Although this species is excessively similar to Desmopachria nitida (No. 236), 

 and allies, it is readily distinguished by the dark colour of the under surface, and 

 the polished, shining, almost absolutely impunctate upper surface. 



In this species the prosternal process takes two difterent forms; in one it is 

 similar to that of Desmopachria nitida, viz., it consists of an anterior part, formed 

 by two raised margins joined to form an acute angle in front, and a posterior part 

 which projects from between these as an acute point ; in the other it is a bifid or 

 furcate process ; the change is effected by the diminution of the central and 

 posterior portion, the greater elevation of the raised sides of the anterior portion 

 and their not being joined in front ; the character is I have little doubt truly a 

 sexual one. 



Brazil, (Santa Rita, August 1830, Sahlberg). 59. 



231. Desmopachria subtilis, n. sp. — Brevis, lata, subrotundata, sat convexa, 

 ferruo-inea, sat crebre et fortiter punctata, prothorace basi utrinque leviter 

 sinuato. Long, fere 2 m.m., lat. 1-J m.m. 



Very closely allied to Desmopachria ovalis, (No. 230), but a good deal smaller 

 and with the punctuation more distant and rather finer : the form of the prosternal 

 process is the same in both species, but I can scarcely think these two forms will 

 prove to be but one species. 



This is one of two species confounded by Aube and described as one species 

 under the name of Hydroporus convex us. 



Brazil, (Campos). 54. 



