On Aquatic Carnivorous Coleoptera. or Dijtiscidcp. 281 



pernitidus, capite thoraceque rufis ; elytris iridescenti-nigricantibus, seriebus 

 punctorum distinctis, lateribus pone humeros profundius excavatis ; corpore subtus 

 rufo-obscuro, capite thorace(jue dilutiovibus, prosterni processu latissimo. Long. 

 41, lat. 24 m.m. 



Very similar toHydrocantlius texanus, but larger and much more convex, and with 

 the thorax more dilated so that the elytra are more excavate at the sides, and the 

 prosternal process is broader. In tire male the prosternal process is closely and finely 

 punctured and a little hollowed in the middle ; while in the female it is flat, shining 

 and impunctate. 



I have not seen any specimen of this species from Mexico, and there is thus some 

 doubt whether it is really the H. atripennis, Say, which was described from Mexican 

 individuals. 



Brazil, (Santa Eita, September, 1850; Boa Sorta, November, 1 850, Sablbcrg) ; (Mexico fide Saj-). 496. 



78. Hydrocanthus debilis, n. sp.— Ovalis, sat convexus, pernitidus, castaneo- 

 testaceus, elytris indistincte undulatim fusco-variegatis, fere omnino impunctatis. 

 Long. 3i, lat. 2S m.m. 



The small size readily distinguishes the species from its allies as yet known to 

 me : the elytra appear at first to be concolorous, but when opened are seen to be 

 variegate by very undulated fuscous marks. The male has the prosternal process 

 densely and finely punctured, and a little impressed, while in the female it is flat, 

 and is coarsely and not densely punctured. 



South America ; Baliia ; Amazon's Valley. 497. 



79. Hydrocanthus funebris, Fairm. Ann. Soc. Fr. 18G9, p. 187. — Ovalis, pos- 

 terius acumiuatus, sat latus, pernitidus, niger, pedibus piceis, antennis rufis ; elytris 

 seriebus tribus obscuris punctorum, lateribus sat sinuatis, spatio inter coxas anteriores 

 sat lato ; prosterni pectorisque medio et laminis coxarum sat crebre punctatis. 

 Long. (!i, lat. 31- m.m. 



There is but little difference between the sexes of this species ; the male has two 

 or three cups on the under side of the second and third joints of the front tarsi. 



Madagascar. 475. 



80. Hydrocanthus advena, n. sp. — Minus latus, convexus, pornitidu.-?, piceus, 

 antennis rufis ; elytris pone humeris vix sinuatis, subUievigatis ; spatio inter coxas 

 anteriores lato, baud elevato ; prosterno impuuctato ; coxarum posticarum parte 

 elevata crebre punctata. Long. f)l m.m., lat. 2^ m.m. 



Basseterre {^ Guadeloupe). The only individual I have seen is in the collection of the Musee Eoyal 

 at Brussels, and is labelled " Basseterre " I am not at all sure what locality is thus intended. 474. 



