On Aquatic Carnivorous Coleoptcra or Dytisache. 273 



is somewhat flattened or depressed, except at the extreme base ; so that the sexes 

 can only be distinguished by the structure of the tarsi. 



South America ; Amazons. (Pampas Germain). .503. 



The individual from the Pampas in M. de Boiivouloir's collection is slightly larger and more convex, 

 and elongate, but if a distinct species it must be a very closely allied one. 



45. Canthydrus brevicornis, n. .sp. — Ovalis, convexus, nitidus, supra nigricans, 

 capite thoracisque lateribus picescentibus, antennis fuscis, basi testaceo ; corpore 

 subtus anterius rufescente, posterius nigricante ; elytris obsoletissime punctatis, 

 seriebusque punctorum subdistinctis ; prosterni processu canaliculate. Long. 2f , 

 lat. li m.m. 



Closely allied to Hydrocanthus nigrinus (No. 47), but not half the size, and Avith 

 the penultimate joints of the antennas much shorter. The only individual I have 

 seen is I think a female, but has only an indistinct impression on each side of the 

 apical ventral segment, 



BrazO, (Parana). 502. 



46. Canthydrus rufipes, n. sp. — Ovalis,sat convexus et elongatus, pernitidus,piceo- 

 rufus, elytris nigricantibus, antennis testaceis; corpore subtus anterius rufo, posterius 

 nigricante ; elytris seriebus duabus sub-distinctis punctorum. Long. 3^ lat. 2 

 m.m. 



Extremely similar to Hydrocanthus nigrinus (No. 47), but rather less convex, a 

 little paler in colour, and the prosternal process without channel. The female has 

 the apical ventral segment impressed on each side. 



Cuba ; Amazons ; (Parana ?). 501. 



47. Hydrocanthus nigrinus, Aube, M.C.— Ovalis, convexus, sat elongatus, 

 pernilidus, supra niger, capite thoraceque versus late ra picescentibus, antennis fuscis, 

 basi testaceo ; corpore subtus anterius rufescente posterius nigricante ; elytris serie 

 punctorum distincta, preterea fere impunctatis; prosterni processu canaliculate. 

 Long. 3i, lat. 2 m. 



The female has a large impression on each side of the apical ventral segment, of 

 which there is no trace in the male. 



South America ; Bahia, (Antilles and Brazil fide Aube). 500. 



48. Suphis lineatus, Horn, Tr. Am. Ent. Soc. 1871, p. 329.— Ovalis, sat convexu.s, 

 nitidus, rafescens, prothorace medio fusco ; elytris sutura vittisque tribus lalis 

 (externa interrupta) nigris; elytris crebre sat fortiter punctatis. Long. 3, lat. ll m.m. 



