48<) On Aquatic Cavuivorous Coleoptera or Dijtiscidai. 



The male has the front and middle tarsi a little dilated, and the inner claw of the 

 front foot longer and thicker than the outer ; joints 3-7 of the autennsB are shghtly 

 stouter than in the female. 



I am not quite sure that the North American specimens may not prove a distinct 

 species, hut I have not specimens of this rare species sufficient to judge from. 

 Leconte has called this North American form H. conoideus. 



Northern Europe, Siberia, aud Vortli America. (Sweden : Finland, to GG' 20' North, Sahlberg ; Britain, 

 Germany, Canada, Lake Superior, Vancouver's hind). 221. 



647. Hydroporus luguhris, Aube, M.C. — Oblongo-ovalis, elongatus, sine pubes- 

 centia, sat nitidus, nigricans, elytrorum epipleuris clypeoque antorius dilutioribua, 

 antennis pedibusqus ferrugineis ; prothorace subtilissime sparsim punctulato, f lytris 

 sparsim conspicue punctatis ; co.xis posterioribus evidcnter elongato-punctatis ; 

 prosterni processu evidenter tricarinato. Long, il, lat. 2m m.ni. 



South -Vnierica, (Monte Video). 22G. 



648. Hydroporus copelatoides, n. sp. — Oblongo-ovalis, elongatus, sine pubosccntia, 

 sericeo-subopacus, nigricans,antennis pedibusque rufesccntibus, corpoi-e supra sparsim 

 subtiliter punctato, subtus fere impunctato, punclis elytrorum subelongatis; prosterni 

 processu medio fortiter carinato. Long. 45, lat. 2| m.m. 



This species bears much resemblance to the European and North American 

 Hydroporus oblongus, but the prosternal process is more carinate along the middle. 



Chili. 225. 



649. Hydroporus advena, n. sp. — Ovalis, sine pubescentia, sat nitidus, niger, 

 supra fusco-testaceus, prothoracis macula magna discoidali elytrorumque sutura 

 ano'ustissime nigricantibus ; thorate subtilissime punctulato, elytris sat crebre et 

 sat fortiter punctatis, punctis subelongatis; corpora subtus nitido fere impunctato ; 

 coxis intermediis sat distantibus, prosterni processu apicem versus latiore; pcdibus 

 antennarumque basi testaceis. Long. 2f, lat. l\ m.m. 



In the male the front and middle tarsi are a little dilated. 



South -Vfriea, (Cape Town). 228. 



