698 On Aquatic Carnivorous Coleoptera or DijtiscidoB. 



This insect differs from D. verrucifer, Sahl., by the greater extension of the dark 

 colour both on the upper and undersurfaces, by the greater number of palettes on 

 the feet of the male, and by the tubercles on the wing-cases of the female being 

 more isolated from one another in the longitudinal direction. The basal black 

 band on the prothorax is very extensive, and reaches the base ; the anterior band, 

 too, nearly if not altogether attains the front margin, and at its extremities is more 

 or less distinctly connected with the posterior black band ; the black colour on the 

 elytra is extremely predominant over the yellow, and the undersurface and hind 

 legs are much blackened. 



Thomson's description of G. piciventris (Sk. Col. X, p. 351) is made up quite as 

 much from specimens of Dytiscus verrucifer as from the present species, and as, 

 moreover, I am quite unable to confirm his statement as to the peculiarities of the 

 posterior claws, on which he largely relied to distinguish his G. piciventris from 

 Dytiscus zonatus, I can scarcely cite him as the first describer of the species, 

 although I have used the name he proposed. 



Lapland. 998. 



1094. Dytiscus bilineatus, de Geer, M.C. — Latus, parum convexus, anterius 

 angustatus, nitidus, testaceus, capitis vertice signaturisque, et prothoracis fascia 

 basali apicalique nigris, elytris creberrime nigro-vermiculatis; elytrorum epipleuris 

 latis. Long. 14^, lat. 9 m.m. 



In the male of this species, the smaller palettes of the front feet are about thirty 

 in number, while those of the middle feet are fourteen in number, six on the basal, 

 and four on each of the two following joints, arranged in two longitudinal series. 



The species is very distinct by the broad epipleurse, as also by the broad form 

 greatly narrowed in front ; the two black bands on the thorax are placed respectively 

 on the anterior and posterior margins, and have but little extension in the antero- 

 posterior direction, the posterior black band gradually thins out, and scarcely 

 reaches the hind angles : the thorax of the female is hardly so long as that of the 

 male, so that the yellow space between the two black bands is scarcely so great in 

 the former sex as it is in the latter. 



The species seems subject to very little variation. 



Euroi)e, (Sweden ; Finland 62° 40' Salilberg ; Belgium ; Germany ; Northern France ; Portugal % 

 "Van Volxem, this latter locality requires confirmation). 999. 



