652 On Aquatic Carnivorous Coleoptera or DytiscidcB. 



The species is smaller in size than D. stagnalis, and has the yellow marks of the 

 elytra much less developed, and the elytrtil apices sinuate in the female : this seems 

 to be all there is to distinguish the two forms, which are perhaps not distinct 

 species. 



The specimen from the Ked River differs from the Finland individual in that it 

 has apparently the claws of the hind tarsi less elongate. 



Northern Europe; North America; (Sweden: Finland 60° 30', Sahlberg; Red River). 1034. 



1011. Dytiscus stagnalis, Fab., Ilydaticus stagiudis, M.C. — Ovalis, latus, ro- 



bustus, subtus uigro-piceus, prosterno capiteque in medio testaceis, supra capite 

 thoraceque rufo-te^taceis, illo in vertice nigro rufo-bimaculato, hoc basi in medio 

 nigro, elytris vittis longitudinalibus nigris a vittis angustulis flavis divisis, margine 

 lateral! fasciaque transversa basali sat discreta, flavis, antennis pedibusque quatuor 

 anterioribus rufis, tibiis intermediis rufo-piceis ; pedibus posterioribus piceis, ungui- 

 culo interno quam externo vix duplo longiore. Long. 14, lat. 72 m.m. 



The male has the front tai'si rather large (but their fringing hairs are scarcely so 

 long as in D. transversalis), and their rather elongate claws are abruptly bent 

 near the base, and are sinuate beneath ; the middle legs are thick, their tai'si 

 broadly dilated, and the patch of dense rough setae at the base is large and 

 conspicuous. The female has some impressions on the lateral parts of the thorax, 

 these seem to be never very extensive, but on the lateral and basal parts of the 

 wing-case there is a large development of this sculpture, which however in certain 

 individuals is greatly reduced, The apex of the wing-cases is rounded in both 

 sexes, but in the female the sutural angle is just visibly produced so as to cause an 

 extremely slight apical sinuation. 



North Europe, Siberia. 1033. 



1012. Dytiscus transversalis, Bergst., Ilydaticus transversalis, il/.C— Ovalis, sat 

 latus, parum elongatus, subtus piceus, prosterno capiteque in medio testaceis, supra 

 niger, capite anterius rufo-testaceo et ante verticem rufo-bimaculato, prothorace 

 anterius et ad latera late rufo-testaceo, elytris margine laterali late fasciaque sub- 

 basali transversa testaceis, antennis pedibusque quatuor anterioribus testaceis ; 

 pedibus posterioribus piceis, unguiculo interiore quam exteriore duplo longiore. 

 Lonor. 13 lat. 7 mm. 



In the male the front tarsi are only moderately large, but their fringing hairs are 

 rather long, their claws are rather small and are simple and gently arcuate ; the 

 middle tarsi are rather broadly dilated, and beneath their patch of dense rough 

 setje at the base (somewhat on the inner side) is distinct but not conspicuous : the 

 female has coarse impressions on the sides of the thorax, which are variable in their 

 extent. In each sex the elytra are simply rounded at the apex. 



