On Aquatic Carnivorous Coleoptcra or DytiscidcB. 507 



694. Dytiscus uliginosus, Linn., Agahus uliginosns, M.C. — Ovalis, convexus, 

 nitidus, niger, supra subsenescens, capite anterius, prothoracis lateribus, elytris 

 humeris et lateribus rufescentibus, antennis pedibusque rufis ; elytris nitidis et 

 obsoletissime reticulatis, i-arius in femina opacis et densissime reticulatis ; prothorace 

 margine laterali lato. Long. 7, lat. 4t m.m. 



This species is of a shorter, broader, and more convex form than its allies. The 

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

 beneath with short glandular hairs, the claws on the front feet are short, and the 

 anterior one is greatly thickened beneath so as to appear angulate, or obtusely 

 dentate about the middle. The female generally resembles the male in sculpture, 

 but a form occurs rarely (? in Britain only) in which the upper surface in this sex is 

 excessively densely and finely reticulate so as to be quite opaque. The species has 

 the hind coxae but little developed ; the prosternal process is moderately broad, 

 and not elongate, its sides a little compressed, and its surface not shining, but feebly 

 punctate ; the mesosternal gi-oove is short and narrow. 



Europe, (S-weden, Finland, Britain, France, Belgium, Alsatia, Germany). 743. 



695. Colymbetes semipunctatus, Kirby, Agahus semipunctatus, M.C. — Oblongo- 

 ovalis, niger, nitidus, supra vix yenescens, capite anterius prothoracisque lateribus 

 rufescentibus, antennis pedibusque rufis ; elytris nitidis, obsoletissime reticulatis, vix 

 punctulatis ; prothorace margine laterali lato. Long. 7, lat. 3^ m.m. 



In the male the front tarsi are short, and, as well as the middle ones, have the 

 three basal joints distinctly incrassate and furnished beneath with short hairs bearing 

 small palettes, the claws of the anterior tarsi ai"e short, and the front one bears an elon- 

 gate acute tooth in the middle beneath. The female I have not seen. The species is 

 undoubtedly nearly allied to Dytiscus uliginosus, but has the prosternal process 

 rather broader and more smooth and shininof. 



o 



North America, (Canada). 747. 



696. Agabus {Gaurodytes) seneolus, Crotch, Tr. Am. Ent. Soc. IV, p. 417. — 

 Ovalis, sat convexus, niger, supra senescens, capite anterius, prothoracis elytrorumque 

 lateribus late rufescentibus, antennis pedibusque rufis ; supra vel nitidus et in 

 elytris obsolete reticulatus subtiliterque punctulatus {$), vel sericeo-opacus, subtilius 

 denseque reticulatus {$). Long. 64, lat. 3i m.m. 



This species is extremely similar in size and form to the European Dytiscus 

 femoralis (No. 72(>). The difference in the appearance of the two sexes is very 

 striking. The male has the basal joints of the front and middle tarsi a good deal 

 thickened, and furnished beneath with moderately long and glandular hairs ; the 



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