66 TERTIARY COLKOPTERA 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, 4!3!, 7319. 117S3, 

 12422. 



BOLKTUHIUS 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 placed 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.fwnditus) 

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

 ences of a similar nature apparently affecting all the Florissant Staphylinidae, 

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



BOLETOBIl S LYKLLI sp. 11OV. 

 PI. VIII, fi-. -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 stria-, 

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

 regularly and gently tapering to a blunt point, the abdomen bevoinl ilic 

 tips of the elytra being half as long again as the rest of the bod v ; 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 largeone, 

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

 Megacronus was proposed l>\ Stephens. 



Length, <>.5 mm.: breadth, 1.4 mm. 



Florissant, Colorado; two specimens, \os. 2'.>!lf>, 1<>S()7. 



