652 On Aquatic Carmvorous Coleoptera or Dytiscide. 
The species is smaller in size than D. stagnalis, and has the yellow marks of the 
elytra much less developed, and the elytral 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 Red River differs trom 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., Hydaticus stagnulis, M.C.—Ovalis, latus, ro- 
bustus, subtus nigro-piceus, prosterno capiteque in medio testaceis, supra capite 
thoraceque rufo-testaceis, illo in vertice nigro rufo-bimaculato, hoe basi in medio 
nigro, elytris vittis longitudinalibus nigris a vittis angustulis flavis divisis, margine 
laterali 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 tarsi rather large (out their frmging 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 tarsi 
broadly dilated, and the patch of dense rough setze 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., //ydaticus transversalis, M.C.-—Ovalis, sat 
latus, parum clongatus, 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 anteriorivus testaceis ; 
pedibus posterioribus piceis, unguiculo interiore quam exteriore duplo longiore. 
Long. 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 
setze 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. 
