On Aquatic Carnivordus Coleoptera or Dijtiscidce^. 4 S3 



impresso, disco sparsim, limbo fortius punctato, elytris crebre distincte punctatis ; 

 coxis pQsterioribus evidenter punctatis ; tarsis articulo 3° magno. Long. 4, 

 lat. 2 m.m. 



There seems to be scarcely any distinction between the sexes of this species. 



Europe. lu springs among moss on moiintiius, (Britain, Geneva, Piedmont, Savoy, Tyrol, Styria). 363. 



Ghoup 7. 



637. Hydroporus picicornis, Sahl., Not. fenn. XIV, p. 1 52. — Oblongoovalis, 

 fere sine pubescentia, niger, subnitidus, antennis padibusque fuscis, illis basi rufo; 

 prothorace medio Irevigato, basi crebre subtiliter punctato ; elytris subtiliter 

 punctatis; coxis posterioribus parce punctatis. Long. 2 J, lat. 1| m.m. 



I have seen but a single individual of this species ; it is without doubt a male ; 

 it has the front tibia3 excised at the base inwardly, and the tarsi broad and parallel, 

 with the third joint more developed than in Hydroporus melanarius (No. 555) and 

 its immediate allies ; the lobes of this joint are however much shorter than they 

 are in the species allied to H. morio (No. 59S) ; and the general form and the 

 absence of pubescence point out an affinity with H. melanarius. The prosternal 

 process is very largely developed ; and in the structure of the coxal articulation 

 the species is allied to H. collaris Lee. 



Europe and Siberia, (Finland, Sahlberg). 399. 



638. Hydroporus collaris, Lee, II ijdroporus stagnulis, M.C. — Subovalis, sine 

 pubescentia, nitidus, rufescens, abdomine pectoreque nigricantibus ; prothorace 

 crasse marginato, medio late Isevi, basi sat crebre punctato ; elytris sparsim 

 subtiliter punctatis ; prosterni processu magno, subplano, ad latera evidenter 

 marginato, medio nullo modo carinato; coxis posterioribus sparsim punctatis. 

 Long. 3l, lat. 2 m.m. 



The only individual I have seen is pi'obably a male ; the front and middle tarsi 

 are broad, and have the third joint well developed; the front tibiae an) excised 

 at the base inwardly. Though very different in appearance from Hydroporus 

 picicornis Sahl. the two species seem closely allied structurally. 



North America, (Lake Superior). 402. 



639. Hydroporus oblitus, Aube, M.C. — Ovalis, sine pubescentia, nitidus, rufo- 

 castaneus, abdomine pectoreque nigricantibus, antennis pedibusque rufis ; pi'othorace 

 latius Ifevi, basi sat discrete punctato ; elytris coxisque posterioribus sparsim 

 punctatis. Long. 3l, lat. If m.m. 



TKA>'3. ROY. DUD. SOC, N.S., VOL. II. • 3 R 



