64 TERTIARY COLEOPTERA OF NORTH AMERICA. 



Tachinus Gravenhorst. 



A genus tolerably rich in species, almost exclusively found in north 

 temperate regions, and of which a couple of dozen occur in North America. 

 The genus has been recognized in amber, but no fossil species, except the 

 following from Florissant, has been described. 



Tachinus sommatus sp. nov. 



PI. VII. fig.s. 8-10. 



Head small, triangular, broader than long, narrowing behind the eyes, 

 smooth, with excessively delicate transverse rugae. The slight remains of 

 the maxillary palpi show that they are not subulate. Antennae reaching 

 almost but not quite to the hind border of the thorax, only slightly enlarg- 

 ing apically, the first four smooth and naked joints differing from those of 

 T. fimbriatus Grav., with which this species agrees well in general appear- 

 ance and size, in that they are not so dilated apically and the fourth joint 

 is scarcely shorter than the third; neither are the fifth to the tenth joints 

 darker colored, and j^ilose as in the modern species, but they are not so 

 uniform, the fifth and sixth, and especially the fifth, being considerably 

 longer than broad, the seventh and eighth equally long and broad as in T. 

 fimbriatus, and the ninth and tenth broader than long; the last joint is pyri- 

 form but no larger than the tenth. Thorax shaped as in T. fimbriatus, smooth, 

 or with faint signs of excessively delicate transverse rugae. Legs, excepting 

 the bases of the femora, not preserved in any of the specimens. Scutellum 

 considerably larger than in T. fimbriatus. Elytra perhaps slightly broader 

 than the thorax, as long as the head and thorax together, the humeral and 

 outer apical angles more rounded than in the modern species mentioned, 

 apically truncate, the surfa,ce with the same transverse microscopic rugae 

 which characterize the head and thorax, and without any punctuation such 

 as is found in all the eight or ten modem species of Tachinus I have seen. 

 Apparently, too, the elytra are of the same light (reddish?) color as the 

 head and thorax, in contrast to the black abdomen, which tapers uniformly 

 to a dull point, the whole body being fusiform, but more pointed behind 

 than in front; the abdominal joints are margined and the surface indistinctly 

 punctate, clothed sparsely with short hairs and with four rows of long 

 spinous hairs attached to the hinder margins, one to a segment in each row, 



