280 On Aquatic Carnicorous Coleoptcra or hytiscidce. 



Closely allied to Hydi-ocanthus australasite, but not so elongate, and of a different 

 colour. 



Siam, (Bangkok); (Cochin China fide Wehncke). 477. 



73. Hydrocanthus oblongus, n. sp. — Oblongo-uvalis, sat convexus, pernitidus, 

 castaneo-ferrugineus, elytris subiridescentibus, fere impunctatls. Long. 4, lat. 2 m.m. 



In the male the prosternal process is deeply hollowed out, and is nearly im- 

 punctate ; and the apical ventral segment has an oblong dull patch in the middle at 

 the apex ; in the female the prosternal process is flat and is punctured in a variable 

 manner ; and the apical ventral segment is quite smooth and shining. 



North America. 492. 



74. Hydrocanthus iricolor, Say. M.C. — Ovalis, sat latus, pernitidus, castaneo- 

 ferrugineus, elytris subiridescentibus, seriebus tribus fere irregularibus et subdis- 

 tinctis punctorum ; antennis minus brevibus. Long. 41, lat. 2^ m.m. 



Larger than Hydrocanthus oblongus, especially broader, and with the antennae 

 more developed, and the elytral series of punctures not altogether effaced. 



North America, (Massachusetts). 493. 



7.5. Hydrocanthus texanus, n. sp. — Ovalis, convexus, pernitidus, ferruginous, 

 elytris nigro-iridescentibus ; corpore subtus posterius plus minusve nigricante. 

 Long. 4i, lat. 2i m.m. 



This species is comparatively more convex than Hydrocanthus oblongus, and 

 H. iricolor, and has the elytra blackish ; in respect of the antennae and elytral 

 punctuation, and of the size it is intermediate between the two. 



Nortli America, (Texas). 404. 



V6. Noterus laevigatus, Brulle. Hydrocanthus IcBvigatus, M.C. — Ovalis, pernitidus 

 castaneo-ferrugineus, elytris paulo obscurioribus indistincte pallido-reticulatis, 

 seriebus punctorum subtilissimis. Long. 5, lat. 2h m.m. 



This species is extremely similar to Hydrocanthus iricolor, but the elytra instead 

 of being concolorous are variegated by irregular pale marks forming a sort of coarse 

 reticulation, this character is not however very conspicuous till the elytra are opened 

 so as to show the light through them. 



South America ; Bahia, Orinoco. 495. 



77. Hydrocanthus atripennis. Say. M.C — Ovalis, sat latus, valde convexus, 



