On Aquatic Carnivorous Colcoptera or Dz/titicida'. 407 



nigris; elytris lineis quatuor integris nigris ; omnium subtilissime densissimeque 

 punctatus fere Isevis, (corpore subtus impunctato). Long. 3->, lat. vix 2 m.m. 



Mas, nitidulus, tarsis anterioribus leviter dilatatis. 



Fern., opaca. 



Var. Lineis nigris elytrorum alternis abbreviatis. 



Europe. (Transylvania, South Eussia.) The variety is from the Caucasus and Persia. 197. 



420. Hydroporus flaviventris, Motsch., M.C. — Ovalis, minus convexus, sine 

 pubescentia, nitidulus, supra capite tboraceque rufo-testaceis, elytris pallide testaceis 

 lineis abbreviatis nigris ; capite evidenter punctato, thorace fere impunctato, elytris 

 omnium subtilissime, densissime vi.x; visibiliter punctulatis, corpore subtus fere 

 impunctato. Long. 3f, lat. 2| m.m. 



il/os, pectore abdomineque nigris, hoc apice rufescente. 



Fern., 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, (Soiigoria, Indersk). 19G. 



421. Hydroporus caspius, Wehncke, Deutsch. Ent. Zeit. 1873, p. 234. — Ovalis, 

 supra minus convexus, sine pubescentia, nitidulus, niger, supra cum antennis pedibus- 

 que testacei.s, vertice lineisque elytrorum nigris ; elytris crebre obsoletissime 

 punctatis, versus suturam punctis sparsis sat distinctis, serie discoidali obsoleta ; 

 coxis posterioribus sparsim obsolete punctatis. Long. Ss, lat. li m.m. 



This species (of which I have seen but a single example) is even more elongate 

 than II. pallidulus (No. 422), and is readily distinguished from it and Dytiscus 

 confluens (No. 423), by the obsolete punctuation of the hind coxiB, as well as by 

 the black colour on the head. 



Europe, (Astrakan). 195. 



422. Hydroporus pallidulus, Aube, 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. 3h, lat. 2 m.m. 



Mas, pectore abdomineque nigris. 



Fern., pectore nigro, abdomine pallido. 



Very similar to Dytiscus confluens (No. 423), but narrower and less convex. 



