April, 1844.] 29 



fous, the former with the terminal joints slightly dusky : thorax dusky reddish- 

 brown, with the margins dull rufous: elytra distinctly punctured, confcrtly at 

 the apex; fuscous, with the sides dark rufous, or testaceous; a slight longitu- 

 dinal impression on the exterior basal angle ; apex acutely rounded : beneath 

 black, glossy : feet, pleurae and epipleurx, dull rufous. 



5. H. dubiu's. Fuscous, minutely reticulate; head, lateral thoracic mar- 

 gins, two spots at the sides of the elytra, and feet, dull red. — 2| 1. long, l£ 1. 

 wide. Pennsylvania. 



Body oblong-ovate: head dull rufous, minutely and densely punctured, lon- 

 gitudinally and deeply indented each side between the eyes: antennx and 

 palpi color of the head ; thorax dark rufous, with the middle of the anterior 

 and posterior margins deeper colored ; strongly punctured, and broadly depress- 

 ed at the posterior and anterior margins : sides widest in the middle, and as 

 much narrowed behind as before: elytra somewhat convex, finely and densely 

 punctured and reticulate, pubescent; four longitudinal elevated obtuse lines, 

 obsolete in some specimens ; fuscous, with the lateral margins rufous from the 

 humerous to near the middle; sometimes a similarly coloured arcuated narrow 

 fascia behind the base ; one or two small obsolete rufous spots before the apex, 

 which is acutely rounded : body beneath very convex, blackish or dark chestnut 

 brown: feet, epijileura and antepectus, dull red. 



Hygrotus, Stephens. 



H. pustulatus. Rufo-lestaceous, with the base and two broad fasciee of the 

 elytra black. — 1£ 1. long, 1 1. wide. Pennsylvania. 



Dytiscus pustulatus, Melsh. MS. 



Head, antennx and palpi rufo-testaceous ; thorax similarly colored, with the 

 middle of anterior margin dusky ; very finely punctate : elytra distinctly and 

 profoundly punctured, glossy ; rufo-testaceous, with the basal edge, and two 

 common broad transverse bands, black, of which the first is near the middle, 

 and the second a little before the apex ; sutural locality between the two bands 

 broadly black: beneath and feet rufo-testaceous. 



Cxclotjs, Eschscholtz — Gyrinus, Linn. 



1. C. opacus. Black, opake ; beneath dark reddish-brown. — 7 1. long, 4^ 1. 

 * wide. Georgia. 



Head at the posterior angles greenish brassy : antennx black-piceous : 

 thorax and elytra almost destitute of gloss, the latter faintly striate towards the 

 lateral margins, strioe obtuse, obsoletely and remotely punctured, with the inter- 

 stices finely and sparsely punctate ; apex ( 5 ) vei T slightly sinuate : beneath 

 and feet dark reddish-brown-piceous. 



Differs from C. vittatus, Germar, in being more broadly oval, in being deeply 

 black, without any brassy tinge, and in the absence of the submarginal cupreous 

 vitta. 



2. C. labratus. Black, glossy ; labrum prominent; beneath rufous or pale 

 testaceous. — 5f 1. long, 3i 1. greatest width. Pennsylvania. — Numerous. 



Gyrinus longimanus, Melsh. Cat. 1086. 

 " dispar, Helwigl 

 " labratus, Harris Cat. ? 



