520 On Aquatic Carnivorous Coleoj^tera or Dytiscidce. 



Group 13. 



Prosternal process acutely raised or carinate along the middle, but its sides little 

 depressed, so that it is not compressed, tlie sides evenly and distinctly margined ; 

 metasternal groove well developed ; swimming legs elongate, rather slender ; wings 

 of metasternum large or moderate ; male front tarsi little incrassate, their claws 

 elongate. 



Two species, found in both the Old and New Worlds. 



724. Dytiseus confinis, Gyll., Agabiis confinis, M.C. — Oblongo-ovalis, nitidus, sub- 

 Isevigatus, niger, elytris fusco-nigris, externe vage rufescentibus, antennis pedibusque 

 rufis, femoribus plus minusve piceis ; elytris vix perspicue punctulatis. Long. 9, 

 lat. 4i m.m. 



In the male the three basal ioints of the front tarsi are but little thickened, and 

 bear beneath small palettes which scarcely appear to be placed on hairs, the claws 

 of the front feet are elongate, little curved, and scarcely sinuate beneath. In each 

 sex the elytra appear smooth and shining, but when cai'efully examined excessively 

 fine and obsolete distant punctui'es are found to exist, and moreover the female has 

 excessively dense and fine regular reticulation. 



Northern Europe, and North America. (Sweden ; Finland to 68° North, Sahlberg ; Lake Superior ; 

 Kansas). 752. 



725. Agabus infuscatus, Aube, Spec. p. 330. — Oblongo-ovalis, niger, prothoracis 

 lateribus vage rufescentibus, elj^tris fusco-nebulosis ad latera pallidioribus, antennis 

 pedibusque rufis, femoribus infuscatis ; elytris densius subtilissimeque reticulatis, 

 minus nitidis, punctis subseriatis et apicalibus subobsoletis. Long. 8, lat. 4l m.m. 



This species is readily distinguished by the peculiar uneven or rugose surface of 

 the intra-linear portions of the hind coxfe. The male has the three basal joints of 

 the front and middle tarsi but little incrassate, and furnished beneath with small 

 palettes which do not appear to be placed on hairs ; the claws of the front feet are 

 elongate and almost straight and simple : the apical portions of the sixth to tenth 

 joints of the antennaa are a little swollen internally at the apex. The sculpture 

 appears to be the same in each sex. 



I have great difficulty in believing this to be Aube's A. infuscatus, though it is 

 so identified by Leconte and others. 



United States of North America, (Lake Superior). 753, 



