.''10 On Aquatic Carnivorous Coleoptera or Dytiscidce. 



Group 9. 



Hind coxae moderate or rather large, wings of metasternum moderate ; prosternal 

 process acuminate, compressed, finely margined ; swimming legs moderately stout ; 

 middle claws of front feet rather long ; elytra marked with yellow. 



Five species from both Old and New Worlds. 



701. Colymbetes t?eniolatus, Harris, Agahus taeniolalus, M.C. — Ovalis, sat con- 

 vexus, nitidus, rufus, vertice et prothorace anterius et posterius senescentibus, elytris 

 testaceis, lineis longitudinalibus latis plus minusve confluentibus seneis ; supra fere 

 laevigatas. Long. 9, lat. 4| m.m. 



The male has the basal joints of the front tarsi (especially the first one), a little 

 thickened, and furnished beneath with rather short hairs which bear small palettes, 

 the claws are somewhat elongate and the anterior one has a small tooth near the 

 base ; the middle tarsi are scarcely thickened but the basal joint is extremely 

 elongate, its length considerably exceeding that of the longest of the two apical 

 tibial spurs ; the intermediate tibiae have their inner edge much emarginate. 



North America, (Peimsylvaiii;i). 761. 



702. Agabus {Gaurodytes) disintegratus. Crotch, Tr. Am. Ent. Soc. IV, p 416. — 

 Ovalis sat convexus, nitidus, rufus, pectore coxisque posterioribus nigricantibus, 

 vertice et prothorace anterius et posterius aenescentibus, elytris testaceis, lineis 

 longitudinalibus vel discretis vel confluentibus aeneis ; supra fere laevigatus. Long. 

 8i, lat. 4t m.m. 



The male has the basal joints of the front and middle tarsi a little thickened, 

 and furnished beneath with rather short hairs which bear small jsalettes; the claws 

 of the front feet are somewhat elongate and the anterior one has a small tooth 

 near the base ; the basal joint of the middle tarsus is somewhat elongate, shghtly 

 exceeding in length the tibial spurs ; the tibiae are quite simple. 



The species is readily distinguished from Colymbetes taeniolatus, by the undersur- 

 face being more or less black, and by the different intermediate legs in the male, and 

 it also has the side wings of the metasternum rather larger. The specimens before 

 me show considerable variation in size and form and markings, and even in some of 

 the structural characters ; the material before me does not enable me to feel certain 

 whether all should be referred to one species or not ; but I am inclined to think 

 this is a species forming more or less localized varieties. 



North America. (Kansas, Ai-izona, Pennsylvania. Nebraska, Canada; sec. Crotch). 762. 



