64 4 On Aquatic Carnivorous Coleoptera or iJytiscidai. 



999. Dytiscus latro, n. sp. — Elongatus ; subtus testaceus, nigro-variegatus, supia 

 niger, prothorace limbo omni elytrisque flavo-margiaatis, actennis pedibusque rufis ; 

 prosterni processu sat elongate ; coxarum processubus prolongatis, angustatis et 

 acutuinatis. Long. 31, lat. 16 m.m. 



This s[)ecies is imperfectly known to me by a single individual, which is an 

 unsulcate female ; it is however undoubtedly distinct ; it has the comparatively 

 elongate and slender form of D. circumflexus, and its coxal processes are inter- 

 mediate between those of D. dauricus and D. circumflexus, being shorter than in 

 the latter, longer than in D. dauricus ; the female is however readily distinguished 

 from the unsulcate females of both of the species alluded to by the great develop- 

 ment of the punctuation on the wing-cases ; this punctuation is rather regular as 

 in D. circumflexus, but is much coarser and has a much greater extension towards 

 the base of the elytra. 



Mantchnria. 948. 



1000. Dytiscus piceatus, n. sp. — Elongatus ; subtus testaceus, metasterno in 

 medio nigricante, supra capite thoraceque nigris, hoc tlavo-marginato, elytris rufes- 

 centibus, flavo-marginatis ; prosterni processu sat elongato ; coxarum processubu.s 

 prolongatis, abrupte angustatis, acuminati-s. Long. 33, lat. IG m.m. 



This species is known to me only by a single male individual ; it is extremelv 

 similar in form to D. circumflexus, and has the small palettes of the dilated tarsi 

 just as in that species ; the colour of the elytra is however reddish, the undersurface 

 is but little marked with black, and the coxal processes are different in form, being 

 rather less elongate than in D. circumflexus, but they are more abruptly narrowed, 

 so that their slender portion is more clearly marked off, somewhat as in O. 

 lapponicus. The punctuation of the apex of the elytra is but slight, even less in 

 fact than in D. circumflexus. 



Eastern Siberia ; (Ii-kutsk). 949. 



1001. Dytiscus circumflexus, Fab., M.C — Elongatus; subtus testaceus, nigro- 

 fasciatus, supra olivaceus, vel viridi-olivaceus, scutello flavescente, prothoi'ace limbo 

 omni elytrisque flavo-marginatis ; antennis pedibusque rufis, tarsis posteriori bus 

 plus minusve picescentibus ; prosterni processu sat elongato ; coxarum processubus 

 valde elongatis, attenuatis, et acuminatis. Long. 33, lat. 16? m.m. Long. 27i 

 35 m.m. 



Alas, nitidus, elytris ad apicem parum punctatis. 



Fern, (o), subopaca, elytris ad basin ultra medium sulcatis, ad apicem crebrius 

 sequaliter punctatis, prothorace undique crebre subtiliter punctato. 



Fern, (h), nitida, elytris ad apicem sat punctatis, prothorace in medio subtilissime 

 punctato, ad latera subopaco et paulo fortius punctato. 



