88 MEMOIRS ON THE COLEOPTERA 



characteristically prominent eyes of the male. Lecontei occupies 

 the more northern geographic range of the genus and is somewhat 

 isolated geographically from the more southern forms by the 

 mountainous regions of central Arizona. The larger scutellum of 

 ceruginis is a rather notable character of that species and, through- 

 out the genus, the clypeal suture comes nearer to revealing itself 

 in its entirety than it does in Plusiotis. 



Cotalpa Burm. 



We come here upon a rather radically different generic type from 

 those which precede, due to the strongly marked transverse clypeal 

 suture, constituting the principal special mark of the group 

 "Areodides" of Lacordaire, and this, together with the entire basal 

 marginal bead of the pronotum, truncate clypeal apex, small 

 scutellum and rounded external contour of the mandibles, serves to 

 distinguish the genus from nearly all the others of the tribe Rutelini. 

 In addition, it may be added that the body is rounded-oval to 

 oblong-oval in form, of more or less pallid coloration above, the 

 head and pronotum with faintly pearly metallic lustre and the 

 elytral punctures only in part serial. The under surface is generally 

 hairy, sometimes conspicuously so, and the larger claw of all the 

 tarsi is unequally split at apex in the male, but simple in the female. 

 The statement made by Lacordaire that the last joint of the tarsi 

 is not dentate beneath is misleading, the anterior is sometimes 

 feebly, the posterior always strongly, dentate. The elytra are 

 never metallic in lustre and are always distinctly and often strongly 

 punctured. The head is generally larger in the female than in the 

 male. This genus is confined to the colder parts of North America, 

 excepting the Pacific coast, but the genus Pocalta, hitherto con- 

 founded with Cotalpa, occurs almost solely on the Pacific coast 

 and thence as far to the southward as Guatemala. The known 

 species of Cotalpa are as follows: 



Basal thoracic bead strong, equal and entire from side to side; legs moder- 

 ate 2 



Basal bead narrowly but completely interrupted at the middle; legs 

 stouter; head very small 7 



2 Head small, never more than half as wide as the prothorax; mandibles 

 without inferior tooth within 3 



Head larger, half as wide as the prothorax or more; body more oblong- 

 elongate; mandibles with an acute tooth within, projecting down- 

 ward from the under surface. Sonoran. .6 



