On Aquatic Carnivorous Colcoptera or Dytiscidce. 271 



but I think the specimens indicate a distinct species, as besides being pale in 

 colour, they are larger and a good deal broader, and have the hind le^^-s more 

 elongate. 



North America, (CarolLaa). 509. 



37. Noterus bicolor, Say. Su2)his bicolor, M.C. — Ovalis, brevis, latiusculus sat 

 convexus, nitidus, ferruginous ; elytris nigricantibus, crebre fortiter punctatis, 

 corpore subtus nigro-rufo. Long. 2i, lat. Ik m.m. 



This species scarcely differs from Suphis gibbulus (No. 38) except by the sexual 

 characters, and that it generally has the elytra and under surface dai-ker in colour. 

 In the male the apical ventral segment is without evident impressions, but in the 

 female it is rather deeply impressed on each side so as to appear somewhat cariuate 

 along the middle. 



United States, (Carolina). 508. 



38. Suphis gibbulus, Aube, Spec. p. 414. — Ovalis, brevis, latiusculus sat con- 

 vexus, nitidus, ferruginous, elytris crebre fortiter punctatis. Long. 2|, lat. 

 vix 1| m.m. 



In each sex the apical ventral segment is depressed on its middle portion, so 

 that the sexes are difficult to distinguish, the depression however is a little greater 

 in the male than it is in the female. 



North America. 507. 



39. Hydrocanthus tenuicornis, Chev. M.C. — Ovalis, sat convexus, nitidus, 

 ferruginous, crebi-e fortiterque punctatus. Long. 2j m.m., lat. 1| m.m. 



This species is very close to Suphis gibbulus (No. 38), but is more elongate 

 and the punctation of the elytra is deejDor. I have seen but one individual, which 

 is a female, and has the aj^ical ventral segment rather deeply impressed on the 

 middle. 



Cuba, (Brussels Museum). 50G. 



40. Canthydrus subsignatus, n. sp. — Ovalis, sat convexus, baud curtus, nitidus, 

 castaneus ; elytris fusco-castaneis, vage testaceo-signatis, crebre fortiter punctatis ; 

 prosterni processu canaliculato ; coxarum laminis parcius punctatis. Long. 21, 

 lat. ll m.m. 



The marks on the elytra are ill-defined ; the lateral margin is yellow, as are 

 also two spots on the middle of each, and some indistinct marks near the suture. 



