446 On Aquatic Carnivorous Coleoptera or DytiscidcB. 



523. Hydroporus addendus, Crotch, Tr. Am. Ent. Soc. IV, p. 393. — Ovalis, latus, 

 sine pubescentia, opacus, rufescen.s, elytris testaceis nigro-signatis ; protliorace 

 anterius et posterius nigricante ; elytris seriebus punctoruna rudimentalibus ; corpore 

 subtus opaco, impunctato, rugis irregularibus ; prosterni processu lato, obtuso. 

 Long. 4j, lat. 2% m.m. 



The four individuals I have seen of this species show me no sexual distinctions. 



California. 223. 



524. Hydroporus funereus, Crotch, Tr. Am. Ent. Soc. IV, p. 392. — Ovalis, 

 elongatus, minus evidenter pubescens, nigricans, supra plus minusve rufo-signatus ; 

 pedibus fuscis, an tennis testaceis extrorsum infuscatis ; corpore dense subtiliter 

 punctato, subtus rugis irregularibus obsoletis ; prothorace versus latera subrugoso, 

 elytris seriebus punctorum interne distinctis externe obsoletis. Long. 5l, lat. 3 m.m. 



I have seen only one individual which has the front tarsi broad, but the claws 

 small ; I do not know its sex. 



California. 267. 



525. Hydroporus oequinoctialis, Clk., M.C. — Ovalis, sat angustus, subtilissime 

 pubescens, fere opacus, nigricans, thorace lateribus et in medio testaceis, elytris 

 sio-naturis parvis minus discretis testaceis, capite in medio indistincte fusco, pedibus 

 antennisque fuscis, his basi testaceo ; prothorace lateribus leviter curvatis, basi 

 elytris angustiore, angulis posterioribus sat obtusis ; corpore dense subtilissime 

 punctato, prothorace minus asquali utrinque subrugoso, elytris seriebus punctprum 

 impressorum sat profundis. Long. 4i, lat. 21 m.m. 



The individual described is a female. 



Mexico. 265. 



526. Hydroporus libens, n. sp. — Ovalis, brevis, convexus, niger, sine pubescentia, 

 vertice, thoracis medio elytrisque j^rope basin obscure testaceo-signatis, an tennis 

 testaceis versus apicem fusco-maculatis, pedibus anterioribus et intermediis fuscis ; 

 corpore obsolete punctato, quasi subla^vigato, baud omnino ojaaco, capite thoraceque 

 subnitidis, hoc basi utrinque longitudinaliter ruguloso ; elytris seriebus suturali 

 aliisque discoidalibus minus distinctis punctorum impressorum. Long. 4, lat. 

 23 m.m. 



In this species the punctuation of the wing-cases and undersurface is excessively 

 obsolete and dense, on the head and thorax it is not so dense and they are distinctly 

 shining ; the rough sculpture at the base of the thorax on each side has amongst 

 it one longer stria which reaches more than half way to the front of the thorax. 



