552 On Aquatic Carnivorous Coleoptera or Dytiscida. 



pedibusque rufis, supra subopacus, densius subtiliusque reticulatus, clytris guttulis 

 duabus pallidis; coxis posterioribus margine extcriore exterue parum curvato. 

 Long. Hi, lat. G m.m. 



The male has the three basal joints of the front and middle tarsi distinctly 

 incrassate, and clothed beneath with rather long hairs which bear minute palettes ; 

 the anterior claw of the front fe(3t is very nearly simple, while the posterior one has 

 its basal portion emarginate beneath and slightly more bent ; the whole of the aj^ical 

 portion of the last ventral segment is covered with coarse longitudinal strise, 

 without any trace of central carina ; the outer claw of the hind foot is accuminate, 

 and differs but little from the inner one except that it is much shorter : in the 

 iemale the apical segment is plicate at the apex, and has the appearance of being 

 rather deeply notched, and it has two or three rugae on each side. 



The species may be readily distinguished from Dytiscus obscurus by the metallic 

 upper surfiice, and by its rather shorter form, as well as by the difl'erent male 

 characters. It varies considerably in size and colour, and the individuals I have 

 seen from North America seem to vary even more than those from Europe ; but I 

 can find no definite characters to distinguish even the extremest specimens that have 

 come under my observation. 



Europe; Arctic Siberia ; North Amei-ica. (Finland to 69°, Sahlberg ; Britain'?; France; Germany; 

 Jenisei ; Hudson's Bay ; Canada). 839. 



784. Ilybius pleuriticus, Lee, Agas. Lake 8up. p. 213. — Ovalis, elongatus, vix 

 convexus, subtus piceus et sub-senescens, supra seneus, limbo anterius vage ferru- 

 gineo, antennis pedibusque quatuor anterioribus rufis, pedibus posterioribus piceis, 

 elytrorum epipleuris feriugineis; supra sub-opaciis, densius reticulatus, elytris guttulis 

 duabus pallidis ; coxis posterioribus subtiliter strigosulis, margine anteriore externe 

 haud subito curvato. Long. 12, lat. 6 m.m. 



The male has the three basal joints of the front and middle tarsi distinctly 

 incrassate, and furnished beneath with long hairs which bear distinct rather large 

 palettes, the anterior claws ai'e rather elongate and each is a little emarginate near 

 the base; the outer claw on the hind foot is rather elongate and thickened, but is 

 distinctly shorter than the inner one, its extremity is sub-obtuse, not at all curved ; 

 the apical ventral segment has a short carina in the middle at the extremity, and 

 is but little rugose on each side : the same segment in the female is plicate, and 

 apj)ears to bear a rather deep narrow notch, and is quite without lateral rugosities. 



North America. 840. 



785. Ilybius inversus, n. sp. — Ovalis, haud elongatus, convexus, subtus piceus et 

 subsenescens, supra seneus, limbo anterius vage ferrugineo, antennis pedibusque 

 quatuor anterioribus rufis, pedibus posterioribus piceis, elytrorum epipleuris ferru- 



