496 On Aquatic Carnivorous Coleoptera or Dytiscidce. 



Group 2. 



Outline ofthorax either slightly discontinuous, or continuous with thatofthe elytra; 

 prosternal process comparatively broad, nearly flat, evenly and distinctly margined, 

 shining and impunctate; metasternal groove moderately broad. Hind coxfe never 

 large ; wings of metasternum large ; coxal lines deeply impressed in their upper 

 part, much prolonged in the anterior and outward direction; hind legs slender or 

 moderate (never stout), their femora little thickened, the postero-external angle 

 slightly obtuse, sometimes rectangular. Male fore feet but little developed, clothed 

 beneath with very short "glandular" pubescence ; sexual ditterences of sculpture 

 slight. 



Seventeen species from both Old and New Worlds. 



668. Agabus hypomelas, Mann., M.C. — Oblongo-ovalis, niger, nitidus, antennis 

 pedibusque rufis, supra sat conspicue tenescens, capite anterius, prothoracis 

 lateribus versus angulum anteriorem, elytrorumque epipleuris vage rufescentibus ; 

 elytris dense subtilissime reticulatis subtiliusque punctulatis; metasterni impressione 

 brevi. Long. 8, lat. 4^ m.m. 



In this species the lateral margin of the thorax is rather fine, and the thorax is 

 rather straight sided, the hind angles being nearly rectangular. The male has the 

 three basal joints of the front and middle tarsi slightly thickened, and turnished 

 beneath with short glandular hairs. The exact position of this species is not easy 

 to define, the prosternal process is short and broad, but is very feebly punctulate 

 at the sides, the metasternal cavity is unusually short, and the coxal lines are not 

 greatly divergent in their upper part ; the side wings of the metasternum are shorter 

 than in Dytiscus guttatus (No. 670). 



North America, (Sitkha, Vancouver's Island). 737. 



669. Agabus styriacus, n. sp. — Oblongo-ovalis, latiuscalus, parum nitidus, niger, 

 supra subaeuescens, antennis palpisque rutis, pedibus piceis, tarsis rufis, elytris guttis 

 duabus testaceis ; prothorace lateribus obliquis, basi quam apice latiore, angulis 

 posterioribus rectis ; elytris undique punctato-rugosulis. Long. 81, lat. 4| m.m. 



The surface of the wing-cases in this species, is rendered rough by a dense, fine, 

 indefinite sculpture which can scarcely be called punctuation ; in the male, even, 

 on the base of the elytra with a high magnifying power, this sculpture does not 

 assume the form of reticulation, but in the female the sculpture is rather coarser 

 and deeper, and gives the appearance of very obscure reticulation and dense 

 rugulosities combined. In the male the three basal joints of the front tarsi are 



