NORTH AMERICAN COLEOPTERA. 7 



that species in many important characters, among others in the dental 

 setae of the mentum, which are very long, approximate, and close to 

 the tooth in this species, while in californicus they are distant from 

 the bottom of the emargination and are widely separated. The pro- 

 thorax in the present species is perfectly smooth and not punctate as 

 in the other ; the surface of the elytra also, in arizonce, is highly 

 polished, while in californicus it is rendered opaque by a minute and 

 regular system of granulation. 



I have before me another male, which must be referred to this 

 species; the prothorax, although not punctate, is transversely creased, 

 as though it had been crumpled while in a plastic state ; the right 

 side of the pronotum is deformed, and as tliere are certain other 

 evidences pointing to its probably abnormal character, I will not 

 describe it ; the posterior angles of the prothorax are narrowly 

 rounded and not produced. 



AMERI^US n. gen. 



This genus is founded upon Dr. LeConte's Bradyeellus linearis, a 

 small elongated insect of very singular form. The principal characters 

 are as follows : — 



Emargination of mentum very small, tooth very long and slender, pro- 

 jecting anteriorly slightly beyond the lateral cusps of the mentum. Second 

 joint of labial palpi as long as the third, strongly bent, bisetose ; second joint 

 of maxillary palpi very robust, strongly flattened, somewhat lunate, third 

 joint scarcely more than one-half as long as the fourth. Penultimate joints 

 of the antennae not appreciably flattened. Labrum transversely truncate 

 anteriorly, feebly bisinuate, angles right and very pronounced, lateral setae 

 nearly twice as long as the intermediate ones. Last joint of anterior tarsi 

 very long, having a very long seta at each side of its upper surface, three 

 penultimate joints wider than long, fourth joint rudimentarily bilobed. 

 Supra-orbital setae single, situated opposite the posterior limit of the eye ; 

 basal mandibular setae wanting ; eyes small, wider than long. Pronotum 

 much longer than wide, median line extremely strong and deep, basal im- 

 pressions very deep, punctate ; elytra more than twice as long as wide. 



The appearance of the insect is unlike that of Bradyeellus, being 

 very long and slender; the pronotum is squarely truncate behind, with 

 the basal angles very slightly obtuse, and not at all rounded. There 

 is but one species described, viz. : — 



A. linearis (Lee.)— Smith. Misc. Coll., 1863-66, vol. vi. p. 16. The 



types in my cabinet were taken in the District of Columbia ; the length is 

 4.5 mill. 



