NORTH AMERICAN COLEOPTERA. 159 



The smallest species known to me and separable from those which 

 precede by the very feebly or not carinate front, and by the basal joints 

 of the antennae paler. 



Three specimens, Arizona. 



TENEBEIONID^. 



€ONOECUS n. g. 



Front feebly trilobed, middle lobe not prominent, separated from the lateral 

 lobes by a feeble sinuation. Labrum trapezoidal, moderately prominent, narrower 

 in front, a median impressed line. Mandibles visible beyond the epistoma, chisel- 

 shaped at apex, the right mandible toothed on the upper side behind the apex, 

 the left mandible simple. Mentum transverse, arcuate in front, entirely closing 

 the buccal opening beneath. Terminal joint of maxillary palpi triangular. Eyes 

 round, slightly emarginate by the sides of the front, rather coarsely granulated 

 without supra-orbital ridge. Thorax fitting the base of the elytra. Scutellum 

 small, transverse. Elytra not wider at base than the thorax, oval, narrowed 

 behind, epipleui'se narrow but entire. Presternum rounded at tip. Mesosternum 

 nearly vertical, slightly concave in front. Metasternum moderate in length, body 

 apterous. Inter-coxal process of abdomen triangular, oval at tip. Legs moderate 

 in leusth. outer edge of tibise rounded, anterior tibise slightly broader at tip, the 

 outer angle somewhat prolonged. Posterior tarsi with the first joint shorter than 

 the fourth, tarsi clothed beneath with short silken hairs. Antennse slender, third 

 joint longer than those following, joints 4-11 gradually shorter and broader, the 

 last three joints being more distinctly broader. 



The uenus which I have found it necessary to form for an inconspicu- 

 ous species belongs to the tribe Gnathosiini as indicated in the Class. Col. 

 N. A. ed. ii. p. BGJ. By the system of Lacordaire the genus should be 

 referred to his group Tribolocarides (Grenera v, p. 69), and seems by de- 

 scription most nearly related to Eremoecus, a Chilian genus, from which 

 it differs in the middle lobe of the front being rounded, by the absence 

 of the supra-orbital ridge, and the structure of the mandibles. 



In the table of genera (Classif. p. 362) Conoecus is more nearly re- 

 lated to Trimytis. The latter genus has the middle lobe of the front 

 prominent, both mandibles dentate above clasping the sides of the mid- 

 dle lobe of epistoma, the first joint' of the hind tarsi is longer than the 

 fourth, and the tarsi spinous beneath. 



C «>vi|)eiiiiis n. sp. — Oblong oval, piceous with a very faint bronze tinge 

 surface finely, very sparsely pubescent. Head coarsely, moderately densely punc- 

 tured, more densely in front. Thorax transverse, about one-half wider than long, 

 base very little wider than the apex, base bisinuate, apex truncate, sides regularly 

 arcuate, hind angles obtuse, disc moderately convex, punctuation finer than on 

 tne head, moderately densely placed, denser at the sides. Elytra regularly oval, 

 base not wider than the thorax, disc with coarse punctures arranged in moderately 

 regular rows but somewhat confused about the scutellum. Prosternum coarsely 



