AMERICAN ENTOMOLOGY. 43 



dark cinereous ; vertex with an elevated, obtuse, dusky line 

 between the stemmata : thorax ferruginous ; anterior angles a 

 little prominent, rounded and concave behind, with an elevated 

 line reaching to the origin of the wings : scutel color of the 

 thorax : wings pale yellowish-brown, with margined nervures : 

 poisers whitish : feet somewhat paler than the thorax : tergum 

 polished ; posterior segments somewhat sericeous ; second, third, 

 and fourth segments, with three abbreviated series of punctures 

 near their bases. 



Obs. During the recent journey of Major Long's party to the 

 source of St. Peter's river, I obtained three individuals of this 

 interesting species, the only one yet found in North America. 

 They occured in a small forest of scattered trees, where we halted 

 at our dining hour, in the immediate vicinity of Wennabea's 

 Sauk village on the Pecktannos. 



None were observed at any subsequent period of the journey. 



LYCUS. Plate XXI. 



Generic character. Head retracted ; antenna approximate, 

 much compressed, more or less serrated ; mouth small, produced 

 into a short rostrum ; maxillary palpi much longer than the 

 labials, terminal joint triangular, truncated ; mandibles at tip, 

 entire and acute : elytra thin and flexible, nearly of equal breadth, 

 or much enlarged towards the tip ; thorax receiving and cover- 

 ing the head, rounded before ; penultimate joint of the tarsi bilo- 

 bated. 



Obs. These insects are somewhat similar in their appearance 

 to the well known " Fire-fly," whose scintillations, on a sum- 

 mer's evening, are scarcely less abundant than the lights of the 

 firmament, which they feebly, and but for a moment, rival. But 

 Lycus is not endowed with the property of yielding light, and it 

 is further distinguished from Lampyris by the somewhat elon- 

 gated mouth, eyes of moderate size, and by the form of the ter- 

 minal joint of the palpi, which is dilated, compressed, and trun- 

 cated at tip. Another kindred genus, Omalisus, of Geoffrey, is 

 in like manner destitute of the curious power of giving light, but 

 the mouth is not rostrated, the second and third joints of the 

 antennae are very short, and the head is only in part covered by 

 the thorax. 



