66 TERTIARY COLEOPTERA OF NORTH AMERICA. 



decidedly particolored markings, and in the bristles on the basal abdominal 

 segment. 



Length, 4 mm.; breadth, 1.25 mm. 



Florissant, Colorado; five specimens, Nos. 266, 4939, 7319, 11783, 

 12422. 



BOLETOBIUS Leach. 



This is a north temperate genus, containing about half a hundred 

 species, about half of which belong to North America. The only fossil 

 species known are the four here described from Colorado. 



The species jjlaced here differ from the modern species of the genus I 

 have seen in" one common character, the proportional shortness of the 

 thorax, more marked in some than in others, but in all but one (B.funditus) 

 strikingly apparent. As, however, this is in accordance with other differ- 

 ences of a similar nature appai-ently affecting all the Florissant Staphylinidaj, 

 there seems to be no ground for hesitation in placing them here. 



BOLETOBIUS LYELLI sp. nOV. 



PI. VIII, fig. 2. 



Head oblong oval, perhaps half as long again as broad, smooth, 

 fusco-testaceous, shining. Antennae imperfectly preserved. Thorax taper- 

 ing a little from base to apex, no longer than the head, smooth, luteo-testa- 

 ceous, shining. Legs short and slender. Elytra considerably broader than 

 the thorax and as long as or a little longer than the head and thorax com- 

 bined, a little wider than long, smooth and shining, fusco-testaceous and 

 apparently with a sutural, a marginal, and a pair of discal sharp strise, 

 scarcely punctured. Abdomen as broad at base as the elytra, beyond 

 regularly and gently tapering to a blunt point, the abdomen beyond the 

 tips of the elytra being half as long again as the rest of the body; the surface 

 smooth, of variable color, the hinder edges of the segments, especially the 

 hinder ones, armed with numerous bristly hairs. The species is a large one, 

 and belongs apparently in the Aacinity of those for which the generic name 

 Megacroniis was proposed by Stephens. 



Length, 6.5 mm.; breadth, 1.4 mm. 



Florissant, Colorado; two specimens, Nos. 2995, 10807. 



