240 COLEOrTERA OF NORTH AMERICA. 



acute tooth on the inner face near the tip. Of Amphidora two 

 species are known to me : A. nigropilosa Lee, and A. littoralis 

 Esch. The type of Stenotrichus is A. ? rufipes Lee, andto the 

 same genus probably may be referred A. atten uata Lee. 



These species are all found on the surface of the ground, but 

 A. littoralis frequently occurs also under bark. 



Group II. — Helopes. 



Body convex, oblong or elongate, rarely oval, apterous, or 

 winged ; upper surface glabrous ; mesosternum short, or moderate 

 in length ; hind coxae narrowly separated ; intercoxal process 

 triangular, obtuse at tip ; outer joints of the antennae subtriangular, 

 compressed. Front and middle tarsi of the male dilated ; pubes- 

 cence of the under surface of the tarsi fine. The epipleurae are 

 narrow, and do not extend to the tip of the elytra. 



Our species are numerous, and some are found in each district. 

 They are generally of a dark, metallic color, with much lustre ; 

 all are to be referred to the genus Helops, and in several of them 

 the flanks of the prothorax are sculptured with deep lines. 



Tribe XV.— MERACAIVTHIIYI. 



Body ovate, convex, apterous; head received in the thorax 

 nearly to the eyes, which are transverse, large, emarginate, and 

 somewhat coarsely granulated ; mouth somewhat quadrangularly 

 prolonged ; front separated from the labrum by a coriaceous 

 clypeus ; sides dilated over the insertion of the antenna?, and 

 obliquely elevated, elevation not extending to the anterior margin 

 of the front (as it does in all the preceding tribes) ; mentum tra- 

 pezoidal ; ligula prominent ; last joint of palpi strongly securi- 

 form ; antennae long and slender, outer joints very slightly thicker ; 

 epipleurae narrow, not extending to the tip of the elytra ; meta- 

 sternum short ; anterior coxa? rounded ; middle coxa? with dis- 

 tinct trochantin ; hind coxae widely separated ; anterior thighs 

 armed with an obtuse tooth, less prominent in the female ; tibial 

 spurs small ; tarsi pubescent beneath. 



This and the next tribe differ from all the others represented 

 in our fauna by a peculiarity first pointed out by Lacordaire, and 

 which led him to name the division of the family, to which they 

 appertain, Otidogenes. In all the tribes above described the sides 

 of the front, above the insertion of the antennae, are horizontal, 



