152 AMERICAN COLEOPTERA. 



By Horn's table this species must be associated with mor- 

 risoni and varipes, from both of which it differs by the less 

 strongly oblong form, more transverse prothorax, non-reticu- 

 late elytra with distant intermixed punctuation, and the 

 longer basal joint of the hind tarsus. In morrisoni the an- 

 tennae are much thicker, the fourth joint less than three times 

 as long as wide, and distinctly longer than the fifth ; the 

 basal joint of the hind tarsus only as long as the next two. 



Ij. nigTOvirescens n. sp. 



Form narrowly oblong, black, elytra with more or less evident dark 

 greenish lustre; legs piceous, the front knees, tibiae and tarsi pale, 

 the middle knees usually more or less so. Antennas piceous, the basal 

 four joints pale, moderately slender, joints 2-3 subequal, together 

 longer than the fourth, the latter three times as long as wide and 

 scarcely longer than the fifth. Head subimpunctate, eyes moderately 

 prominent. Prothorax one-fourth wider than long, widest in front of 

 the middle, sides rather strongly arcuate anteriorly, sinuate posteriorly, 

 front angles thickened, hind angles obtuse but sharply defined and 

 slightly prominent, punctuation very sparse and minute, scarcely per- 

 ceptible toward the middle of the disk. Elytra parallel, nearly twice 

 as long as wide, three-fifths wider than the prothorax, very finely 

 reticulate, finely rather sparsely punctate. Hind tibiae straight ; basal 

 joint of hind tarsus as long as the next two. Last ventral of male 

 broadly truncate behind, of female, oval. Length, 3.4-3.8 mm. ; 

 width, 1.5-1.6 mm. 



Florissant, Colo. (Cockerell); eight examples, on flowers 

 of Juncus. 



This species is also allied to morrisoni and varipes. As 

 compared with the former it is smaller, much less brilliant 

 in color, with rather more slender antennas, the fourth joint 

 not longer than the fifth, the punctuation finer throughout. 

 It differs from varipes also in its smaller size, duller color, 

 and in having the prothorax more transverse and the hind 

 tibiae straight in both sexes. 



HALTICA Geoff. 



The species of this genus constitute a difficult study, and 



in making known some of the nondescript material which 



has accumulated in my cabinet, it has been hard to decide 



where to stop. We know as yet far too little of the extent 



