On Aquatic Carnivorous Coleoptera or Dyiiscidce. 403 



This species was described by Sahlberg as Coelambus unguicularis, but as Crotch 

 had recently described another species under that name, I have been obUged to 

 find a new one for Sahlberg's species. 



Siberia, (Jenisei, July, 187G, Dr. J. SahU.erg). 458. 



408. Hydroporus dissiinilis, Har., M.C. — Ovalis, convexiusculus, nitidus, sine 

 pubescentia, ferrugineus, abdomine pectoreque nigris ; elytris sat crebre insequahter 

 punctatis; corpore subtus nitido, coxis posteriori bus fortiter punctatis. Long. 4, 

 lat. 2| m.ni. 



I have seen but a single female of this species which is very close to the more 

 sparingly punctured forms of Dytiscus impresso-punctatus, (No. 409), but is very 

 shining beneath. 



North America, (Illinois, Lake Superior, New York). 207. 



409. Dytiscus impresso-punctatus, Schall., Hijdroporus picipes, M.C. — Oblongo- 

 ovalis, sat angustus, convexiusculus, glabriculus, pectore abdomineque nigris, supra 

 obscure ferrugineus, vertice utrinque, prothorace basi elyfcrisque lineis indistinctis 

 nigricantibus ; elytris basi fortiter profunde infequaliter punctatis, stria suturali 

 aliisque duabus externis punctorum ad basin impressis, apicem versus dense fere 

 gequaliter punctatis ; coxis posterioribus crebre, fortiter profunde punctatis. Long. 

 5, lat. 2 1 m.m. 



Mas, tarsis anterioribus et intermediis bene dilatatis, anterioribus unguiculo 

 interno leviter incrassato. 



Fern., (a) ut in mare punctata et nitida. 



(6) omnino opaca, elytris dense gequaliter magis subtiliter punctatis, 

 seriebus punctorum impressis obsoletis. 



This species varies greatly in size, colour, and in the punctuation of the upper 

 surface ; in some of the varieties the impressed series of punctures are scarcely to be 

 distino-uished. 



H. decemlineatus, Mann, and H. picatus, Kirb. , are North American varieties. 



Europe and Asia Minor, Siberia, Sitka, and United States of North America. 205. 



410. Coelambus elevatus, n. sp. — Ovalis, convexus, breviusculus, nitidus, testaceo- 

 ferrugineus, elytris lineis elongatis, alternis ad basin abbreviatis, fuscis; coxis 

 posterioribus externe parce punctatis. Long. 4, lat 2i m.m. 



This species is very similar to H. saginatus, Schaum, (No. 412), but is much 

 shorter, and the under surface is pale : the only individual I have seen is a female, 

 the wing-cases are shining at the base, and the punctuation there consists of not 



TBANS. HOT. PUB. SOC, U.S., VOL. II. 3 G 



