On Aquatic Carnivorous Colcoptera or DijtiscidcB. 453 



This species differs from Dytiscus granularis by the more elongate form and 

 different sexual distinctions, as well as by some other minor characters. 

 Bedel states by error that this species is the male of Dytiscus granularis. 



Europe. Rarer than D. granularis, and not extending so far to the North : absent from Britain and 

 Scandinavia. 313. 



543. Hydroporus nigritarsis, Sahl. n. sp. — Elongato-ovalis, parum convexus, 

 parce subtiliter punctatus et pubescens, nigricans, elytris externe testaceis, sutura 

 late irregulariter nigra, parte testacea linea fusca vaga vix divisa : pedibus rufis, 

 tarsis posterioribus obscuris, antennis fuscis basi rufo ; prothorace versus latera stria 

 impressa abbreviata, extus eamdem testaceo ; corpore subtus sat nitido, coxis 

 posterioribus parce obsolete punctatis. Long. 2|, lat. li m.m. 



The only character I can point out to distinguish this species from H. bilineatus, 

 is that the elytra have their external portion broadly testaceous, instead of having 

 the two yellow lines of H. bilineatus. I do not know the male : so I cannot say 

 whether the sexual characters will prove it to be a good species or not. 



Northern Siberia. 314. 



544. Hydroporus varius, Aube, M.C. — Ovalis, sat convexus, parce subtilissime 

 punctatus et pubescens, sat nitidus, niger, prothoracis lateribus pedibusque testaceis, 

 antennis fuscis basi testaceo, elytris nigro testaceoque variegatis, signaturis 

 irregularibus : thorace utrinque stria impressa plus minusve abbreviata ; pectore 

 parcius sat distincte punctato. Long. 2l, lat. I3 m.m. 



Mas, tarsis anterioribus leviter dilatatis, unguiculis vix elongatis. 



This species varies greatly in size and in the markings of the elytra ; sometimes 

 the elytra are yellow with the suture broadly black, the basal portion of this band 

 being narrower than the middle ; behind the middle this sutural band sends off a 

 prolongation on each side ; the shoulder has a black mark which is connected along 

 the base with the sutural band, and towards the side there is a large irregular dark 

 mark ; these markings become confluent at different points so as to give rise to a 

 great variety of patterns, and sometimes the elytra are nearly entirely black. 



Hydroporus bihamatus (Chev. Rev. Zool. 1861, p. 149), is founded on small 

 Algerian individuals of this species ; and H. ignotus, JMuls. (Ann. Soc. Linn. Lyons, 

 VIL, p. 305), appears to be a similar variety. 



Southern Europe, and Algeria. 315. 



545. Hydroporus Iteticulus, n. sp. — C)valis, convexus, parce subtilissime punctatus 



et pubescens, sat nitidus, niger, an tennarum basi, prothoracis lateribus, pedibus elytris- 



que testaceis, his plaga irregular! suturali, macula humerali signaturisque externis 



3 N 2 



