120 



NORTHERN ZOOLOGY. 



B. Elytris unistriatis. 



(170) 2. Hydrobius marginellus. Marginal Hydrobius. 



Hydrobius marginellus. Steph. lllustr. Mandib. ii, 131, 11 ? 



Hydrophilus marginellus. Fab. Ent. Syst. i, 185, 17 ; Syst. Eleuth. i, 252, 19. Illig. Kaf. Preuss. i, 246, 5. Herbst. Ins. 

 vii, 303, 10, t. cxiv, /. 2, b. Panz. Ent. Germ, i, 71, 7. Haw. Ent. Trans, i, 85. 



affinis b. Gyll. Ins. Suec. iv, 277, 12. 



margipallens. Marsh. Ent. Brit, i, 408, 21. 



Length of the body 1§ line. 



Two specimens taken in Lat. 54°. 



DESCRIPTION. 



Body subelliptical, convex, minutely punctured, black ; above glossy. Palpi and antenna? dusky 

 rufous ; knob of the latter black : sides of the prothorax, and the anterior margin dusky rufous : 

 elytra with a single furrow adjoining the suture ; sides dusky rufous : tibiae dusky rufous; tarsi rufous. 



I have subjoined a mark of interrogation to the synonym of Mr. Stephens, because he describes 

 his specimens as having an impression above each eye, and two larger ones in the disk of the pro- 

 thorax, which are not discoverable in the American specimens, nor in the British specimen described 

 from my cabinet by the late Mr. Marsham, under the name of H. margipallensA 



(171) 3. Hydrobius melanocephalus. Black-head Hydrobius. 



Hydrobius melanocephalus. Steph. lllustr. Mandib. ii, 129, 5. 



Hydrophilus melanocephalus. Oliv. Ins. iii, n. 39, 14, 10, t. ii, /. 12, a. b. Fab. Syst. Eleuth. i, 253, 23. Gyll. Ins. Suec 

 i, 119, 9. Illig. Kaf. Preuss. i, 246, 6 ; Mag. i, 66, 6 ; Ent. Trans, i, 86. 



minutus. Payk. Fn. Suec i, 182, 6. 



4punctatus. Herbst. Ins. vii, 305, 12, t, cxiv, f. 4, i>. 



Length of the body 2^ — 1\ lines. 



Two specimens taken in Lat. 54°. 



4 There appears to be an error of the press in the statement of the length of this species in Mr. Marsham's work- 

 instead of J it should have been If line, which is the length of the specimen from which his description was taken. 



