494 On Aquatic Carnivorous Coleoptera or Dytiscide. 
Group 1. 
Outline of thorax very discontinuous with elytra; prosternum but little thickened 
in the middle in front ; swimming legs elongate and slender, their femora feeble, 
with rounded postero-external angle ; metasternal cavity ill-developed. 
Six species, from both Old and New Worlds. 
662. Agabus (Anisomera) cordatus, Lec., Anisomera cordata, M.C.—Suboblongus, 
depressus, niger, supra venescens, capite rufescente, antennis tarsisque 4 anterioribus 
geniculisque rufis; prothorace transverso, basi fere truncato, elytris angustiore, 
lateribus sinuatis, anterius rotundatis, angulis posterioribus rectis, Long. 11, lat. 
> m.m. 
This species is very readily recognized by the form of the thorax. The legs are 
slender, and the claws elongate ; the sculpture is that of the Agabus guttatus allies. 
I have seen but a single individual which is a male, and has the three basal joints 
of the front and middle tarsi a little thickened, and furnished beneath with glandular 
hairs. 
North America, (Kansas). 720. 
663. Agabus cephalotes, Reiche, M.C.—Fere oblongus, depressus, nigro-piceus, 
nitidus, antennis pedibusque rufis, prothoracis lateribus dilutioribus ; prothorace 
elytris angustiore, lateribus antrorsum subrotundatis, posterius leviter angustatis, 
angulis posterioribus paulo obtusis ; superficie haud coriaceo ; elytris punctis magnis 
posterius irregularibus, antrorsum in seriebus tribus ductis. Long. 92, lat. 4 m.m. 
The shining surface and peculiar form of this species render its recognition very 
easy. There is no difference of sculpture in the sexes; in the male the two basal 
joints of the front and middle tarsi are scarcely thickened, but are furnished beneath 
with glandular hairs. 
Corsica. 721. 
664. Agabus caraboides, n. sp.—em., Ovalis, fere depressus, niger, antennis pedi- 
busque concoloribus,elytris fuscis ; prothorace basi quam elytris evidenter angustiore, 
Brullé (No. 1207) ; Chilii—Colymbetes annulatus, Zoub. (No. 1212); Tureomania.—Colymbetes bicolor, 
Kirb. (No. 1215); North America.—Colymbetes impressus, Zoub. (No. 1231); Turcomania.— 
Colymbetes latus, Gebl. (No. 1236) ; Siberia. 
The position of the following species is quite doubtful -—Agabus hydroporoides, Murr. (No. 1191) ; 
West Africa. 
