STAPHYLINID.K. 65 



one row at the sides, and one row laterodorsal. The fifth segment is only 

 about half as long again as the preceding, (littering markedly in this respect 

 from the modern species; llie last dorsal segment is quadridentate (in the 

 female), resembling most in this respect the much smaller American species 

 '/'. t(iclt</fn-i>i<li'x and T. rrjHtiH/itx Horn, lint the lateral teeth are broader and 

 more conical than in either of these, a feature which is not found in any of 

 the species figured by Horn. They are slightly distorted in the specimen, 

 the outer one on the right side being evidently not fully displayed. 



Length, 7.5 mm.; breadth, 2.5 mm. 



Florissant, Colorado; five specimens, Nos. 548, 3395, 3446, 75X1, 

 12058. 



TACHYPORUS Gravenhorst. 



This genus is moderately rich in species, almost exclusively found in 

 north temperate regions, and of these more than half a dozen occur in the 

 United States. In the older Tertiaries, single species occur at Florissant 

 and Kott, and the genus has been recognized in amber. 



TACHYPORUS NIGRIPENNIS sp. nov. 

 PI. VIII, fig. 1. 



Head rounded, short, triangular, smooth, and piceous. Antennae 

 reaching to the end of the thorax, enlarging gradually and slightly, testa- 

 ceous. Thorax luteous, smooth, and shining, just twice as broad as long, 

 scarcely narrower than the elytra, the sides narrowing strongly toward the 

 apex, rounded, especially at the angles, squarely truncate at base. Elytra 

 together nearly half as wide again as long*, longer than the head and thorax 

 together, squarely truncate at apex, the humeral angles well rounded, the 

 surface smooth, with occasional short bristles, and testaceous, deepening to 

 piceous on the basal two-thirds and sometimes including the whole of the 

 elytra. Abdomen narrower at base than the tip of the elytra, tapering 

 regularly to a rounded point, piceous on apical, dark testaceous on basal 

 half, the tips of the segments and to some extent the other parts at the 

 sides furnished with black bristles, the edge of the basal segment with four 

 rather large equidistant bristles just at the tip of the elytra, not preserved 

 in the specimen figured. It seems to agree well in size and general 

 appearance with our T. jocosus Say, but differs from all our species in its 



MON XL 5 



