558 On Aquatic Carnivorous Coleoptera or Dytiscide. 
796. Ilybius obtusus, n. sp.—Ovalis, haud angustus, subdepressus, fere opacus, 
niger, supra nigro-subzeneus, antennis crassiusculis rufis, articulo ultimo apice fusco, 
pedibus piceis; prothorace margine laterali lato ; elytris densius minus subtiliter 
reticulatis, et versus apicem fere punctatis, punctis subseriatis magnis; coxis 
posterioribus subobsolete reticulatis, margine anteriore minus curvato; prosterni 
processu minus elongato. Long. 94, lat. 5 m.m. 
The female has a plica or fold in the middle of the apex of the last ventral 
segment, which does not project backwards at all. 
I have seen only a single individual of this species, which seems to be a very 
distinct one, only likely to be confounded with I. eenescens, and Dytiscus angustior 
(Nos. 790 and 791), which it resembles in size, and its little elongate prosternal 
process; but the much more conspicuous sculpture of the elytra will make the 
determination of this species very easy. 
Eastern Siberia. 850. 
797. Dytiscus biguttulus, Germ., Ins. sp. nov. p. 29.—Ovalis, fere brevis, 
convexus, subtus piceus, supra nigro-zeneus, limbo anterius minus ferrugineo, 
elytrorum epipleuris ferrugineo-zneis, antennis pedibusque anterioribus rufis, 
pedibus posterioribus piceis; supra sub-opacus, elytris densius subtiliusque 
reticulatis, guttulis duabus pallidis, quarum posteriore conspicua ; coxis posteriori- 
bus subtiliter strigosulis et punctatis, margine anteriore extus abrupte curvato ; 
prosterni processu elongato. Long. 92, lat. 53 m.m. 
The male has the basal joints of the front and middle tarsi a little incrassate, and 
furnished beneath with moderately long hairs which bear small palettes; the claws 
of the front feet are not elongate, the anterior one is very slightly, the hinder 
rather deeply, emarginate near the base; on the hind feet the outer claw is 
acuminate, and differs only slightly from the inner, except in its length ; the apical 
ventral segment, has a rather short carina along the middle of its apical portion, 
and its hind margin is only obscurely rugose from a slight elongation of the 
punctures which it bears ; the female has the apex of the last segment, with a short 
plica, and a rather broad short apical emargination, and is smooth at the sides, 
This species is shorter in form than any of the three preceding; and is 
smaller than J. subeeneus No. (789), and has the front border of the hind coxe 
more abruptly deflexed at its outer part. It greatly resembles I. oblitus (Ne. 801), 
but is distinguished by the less approximation of the front border of the hind coxee 
to the middle coxal cavity. 
North America. 843. 
798. Ilybius similis, Th., M.C.—Ovalis, convexus, niger, subtus nigro-piceus, 
antennis pedibusque quatuor anterioribus rufis, pedibus posterioribus rufo-piceis, 
