On Aquatic Carnivorous Coleoptera or Dytiscide. 407 
nigris; elytris lineis quatuor integris nigris ; omnium subtilissime densissimeque 
punctatus fere levis, (corpore subtus impunctato). Long. 32, lat. vix 2 m.m. 
Mas, nitidulus, tarsis anterioribus leviter dilatatis. 
Fem., opaca. 
Var. Lineis nigris elytrorum alternis abbreviatis. 
Europe. (Transylvania, South Russia.) The variety is from the Caucasus and Persia. 197. 
420. Hydroporus flaviventris, Motsch., M.C.—Ovalis, minus convexus, sine 
pubescentia, nitidulus, supra capite thoraceque rufo-testaceis, elytris pallide testaceis 
lineis abbreviatis nigris ; capite evidenter punctato, thorace fere impunctato, elytris 
omnium subtilissime, densissime vix visibiliter punctulatis, corpore subtus fere 
impunctato. Long. 33, lat. 25 m.m. 
Mas, pectore abdomineque nigris, hoc apice rufescente. 
Fem., subtus rufo-testacea. 
This species is very similar to Hydroporus pallidulus, Aube (No. 422), but is 
rather more elongate, and is readily distinguished by its more obsolete sculpture ; 
the punctuation on the wing cases is so fine that it is not very easy to detect it, 
and the punctures of the undersurface are also obsolete. 
Western Asia, (Songoria, Indersk). 196. 
421. Hydroporus caspius, Wehncke, Deutsch. Ent. Zeit. 1873, p. 234.—Ovalis, 
supra minus convexus, sine puvescentia, nitidulus, niger, supra cum antennis pedibus- 
que testaceis, vertice lineisque elytrorum nigris; elytris crebre obsoletissime 
punctatis, versus suturam punctis sparsis sat distinctis, serie discoidali obsoleta ; 
coxis posterioribus sparsim obsolete punctatis. Long. 82, lat. 13 m.m. 
This species (of which I have seen but a single example) is even more elongate 
than H. pallidulus (No. 422), and is readily distinguished from it and Dytiscus 
confluens (No. 423), by the obsolete punctuation of the hind coxz, as well as by 
the black colour on the head. 
Europe, (Astrakan). 195. 
422. Hydroporus pallidulus, Aubé, M.C.—Ovatus, crassus, sat convexus, supra 
pallido-testaceus, infra (ex parte) niger; elytris quatuor lineis abbreviatis prater 
suturam utrinque nigro-ornatis, subtilius punctulatis; coxis posterioribus crebre 
fortiter punctatis. Long. 32, lat. 2 m.m. 
Mas, pectore abdomineque nigris. 
fem., pectore nigro, abdomine pallido. 
Very similar to Dytiscus confluens (No. 423), but narrower and less convex. 
