172 Journal New York Entomological Society. [Vol. xm. 



the finer pubescence of the antennae beginning on the fourth joint. 

 Badiipennis, in its rounded posterior thoracic angles, departs some- 

 what in facies from the other three. Regarding these four species 

 together with two undescribed forms in my collection as exponents of 

 the genus, the latter may be characterized as follows : 



Genus TACHYCELLUS Morawitz. 



Penultimate joint of labial palpi not longer than the terminal joint and bisetose 

 in front; front and middle tarsi of males with two rows of squamules beneath, the 

 former moderately, the latter (except rarely) feebly or scarcely dilated, the fourth 

 joint emarginate ; mentum toothed ; finer pubescence of the antenna; commonly begin- 

 ning on the fourth joint, more rarely at the middle of the third ; body throughout 

 glabrous ; side margin of prothorax with a single seta before the middle ; elytra nor- 

 mally striate and with a single dorsal puncture ; presternum non-setose at tip ; abdomen 

 without pubescent spot in the male. 



Table of Species. 

 Antennae with three glabrous joints. 



Hind angles of thorax sharply defined and nearly rectangular. 

 Legs pale. 



Prothorax testaceous, with large piceous spot ; width at base not 



greater than the length atrimedius. 



Prothorax piceous, marginal bead alone paler ; width at base a little 



greater than its length kitbyi. 



Legs piceous, the tibia; paler at base conformis. 



Hind angles of thorax obtuse, rounded badiipennis. 



Antenna? with two glabrous joints, the third pubescent in outer half, though less 

 conspicuously so than the following joints. 

 Hind angles of thorax rectangular, middle tarsi scarcely dilated in the $ . 



nigrinus. 



Hind angles of thorax obtuse, scarcely rounded ; middle tarsi of male nearly as 



widely dilated as the front tarsi turbatus. 



T. atrimedius Say, Trans. Am. Philos. Soc, II (1823), p. 39. 



" Length 7 mm. Black ; prothorax and elytra testaceous, the former with a 

 large quadrate black spot, the latter with a dusky cloud divided by the suture ; body 

 slender ; prothorax distinctly narrowed behind ; hind angles subrectangular, slightly 

 prominent, not rounded ; basal impressions broad, punctured ; antenna; with joints 

 1-3 testaceous, legs testaceous." (LeConte's description.) 



Occurs from New England and Canada to Texas. Always easily 

 recognizable by its coloration. 



T. kirbyi Horn, Pull. Brook. Ent. Soc. VI (18S3), p. 51. 



Length 6 mm. Blackish, the elytra gradually becoming castaneous or piceo- 

 castaneous toward the base and sides ; epipleura;, marginal bead of thorax, legs, and 

 basal three joints of antenna' paler. Prothorax moderately narrowed behind, the 



