506 On Aquatic Carnivorous Coleoptera or Dytiscide. 
692. Agabus punctatus Melsh., Proc. Ac. Phil. II, p. 27.—Ovalis, sat convexus 
nitidus, rufescens, abdomine pectoreque piceis, supra zenescens ; elytris subleevigatis, 
haud reticulatis, vix perspicue punctulatis; prothorace sat magno. Long. 73, 
lat. 43 m.m. 
The male has the three basal joints of the front and middle tarsi distinctly incras- 
sate and furnished beneath with rather short hairs which bear small but distinct 
palettes ; the claws of the front feet are shorter and more curved than in the female 
and have a small obtuse tooth at the base ; the long apical spur of the hind tibia 
is also thicker than in the female, and has its underside longitudinally striate. 
The species varies in the colour of the upper surface, which is sometimes more 
rufescent, sometimes more eeneous; and the serial punctures of the elytra are in 
some individuals coarser than in others. 
North America. (Pennsylvania, Georgia, sec. Crotch). 778. 
693. Agabus eruginosus, Aubé, M.C.—Ovalis, sat convexus, nitidus, rufescens, 
abdomine pectoreque piceis, supra subeenescens ; elytris subleevigatis, haud reticulatis, 
subtilissime punctulatis ; prothorace sat magno. Long. 7%, lat. 4¢ m.m. 
In the male the front and middle tarsi are almost without dilatation, and have only 
a very small surface beneath clothed with hairs ; the claws of the front feet are short 
and have a small swelling at the base ; the intermediate femora bear a dense elon- 
gate pubescence, and the intermediate tibize a more scanty and short pubescence ; 
the hind margin of the posterior femur forms a curve owing to the outer and 
hinder angle being considerably produced and acute. 
This species I should have failed to distinguish from A. punctatus had it not been 
for the remarkable male characters; in nearly all particulars except the sexual 
peculiarities the two species seem excessively similar; Agabus eruginosus will 
probably prove to be less convex, and more rufescent or less zeneous above, and to 
have the fine punctures on the elytra not quite so obsolete : the only good character 
to distinguish the females will I think be found in a different arrangement of the 
punctures on the apical ventral segment. 
North America. 779. 
Group 7. 
Hind coxe small, wings of metasternum large, hind tarsi feeble, but hind femora 
with a distinct lamina at postero-external angle ; male front claws short and dentate 
beneath ; no abdominal file ; prosternal process not, or only slightly, compressed, 
glabrous or feebly punctate, either narrow or moderately broad ; cilize at angle of 
lower surface of hind femur very rudimentary. 
Three species from both Old and New Worlds. 
