498 On Aquatic Carnivorovs Coleoptcra or DytiscidcB, 



672. Agabus americanus, Aub^, M.C.-— Oblongo-ovalis, nigricans, nitidiis, antennis 

 palpisque rufis, pedibus anterioribus rufo-piceis, posterioribus fere nigris ; prothorace 

 lateribus subrectis, angulis posterioribus obtusis, rotundatis, margine laterali elevate; 

 elytris nullo mode reticulatis, laevigatis, punctis subseriatis conspicuis. Long. 8i, 

 lat. 4 m.m. 



The male has the basal joints of the front tarsi a good deal incrassate, and much 

 compressed, and rather extensively furnished beneath with short glandular 

 pubescence ; the anterior claws are rather elongate and sinuate. The terminal joint 

 of tlie middle tarsi is elongate and slender. 



I have seen only Aube's type of this species, which appears to be a very distinct 

 one, by the smooth shining surface, and the indistinct rounded hind angles of the 

 thorax. 



Mexico, (coll. Mnizech). 11.54. 



673. Colymbetes seriatus. Say, Agabus seriatus, M.C. — Oblongo-ovalis, niger, 

 supra senescens, nitidus, antennis palpisque rufis, pedibus piceis ; prothorace 

 lateribus obliquis, basi subtruncato, angulis posterioribus rectis ; elytris subtilius 

 reticulatis, versus apicem evidentius reticulatis, sed neque opacis nee rugosis. Long. 

 9, lat. 4f m.m. 



This species is closely allied to Dytiscus guttatus (No. 670), but is rather larger, 

 and has the sculpture of the upper surface finer, and similar in both sexes ; the 

 prosternal process is larger and more acutely pointed at its apex. The male has 

 the three basal joints of the front and middle tarsi a little thickened and furnished 

 beneath with glandular hairs ; the anterior claw of the front feet is a little dilated 

 near the base so that its lower edge is slightly sinuate. 



The species seems to be widely distributed in North America and is somewhat 

 variable in form and sculpture. 



North America. (Canada, California). 727. 



674. Agabus perplexus, n. sp. — Oblongo-ovalis, niger, supra aenescens, antennis 

 pedibusque piceis ; prothorace brevi antrorsum angustato, angiilis posterioribus sub- 

 rectis ; elytris dense subtiliter reticulatis, retis versus apicem baud omnino minutis. 

 Long. 9, lat. 5t m.m. 



In the male the basal joints of the front and middle tarsi are distinctly thickened 

 and furnished beneath with glandular hairs ; the anterior claw of the front feet has 

 the basal portion slightly thickened, so as to cause the outline beneath to be slightly 

 sinuate. 1 he species is closely allied to Colymbetes seriatu.s, but the lateral portions 

 of the metasternum are not quite so much reduced in size. 



North America, (California, Vancouver's Island). 



