142 COLEOPTERA OF NORTH AMERICA. 



riosa, from the copper-mines of the Gila, of a pale green color, 

 with the margins of all the parts of the body and broad stripes 

 on the elytra of a pure polished gold color, is the most beautiful 

 Coleopterous insect known to me. 



But two groups are found in our country, and in both the 

 labrum is horizontal, short, and sinuate, and the mentum quadrate. 



Elytra with a membranous margin. Anomaly. 



Elytra without membranous margin. Rutel.e. 



Group I. — Anomalse. 



These insects are of small size, have 9-jointed antennas, and the 

 mandibles in repose do not project beyond the clypeus. Only 

 two genera occur in our fauna, and neither has yet been found on 

 the maritime Pacific slope of the continent. One of the anterior 

 and middle claws is cleft in all of our species. 



A. Epimera of the mesothorax inferior; elytra not emarginate at base ; 



Prosternum not prominent behind the coxae ; clypeus parabolic. 



Anomala. 



B. Epimera of the mesothorax ascending ; elytra emarginate at base; 



Clypeus parabolic ; prothorax sulcate or impressed. Strigoderma. 



The species of the last-named genus have the elytra flattened 

 and deeply sulcate ; but two are included in our territory. 



Group II.— Rutelae. 



Insects of moderately large size, having 10-jointed antennae, 

 and prominent mandibles ; none have yet been found on the Pa- 

 cific slope. Our genera belong to the sub-groups Pelidnotse and 

 Areodae, both having the thorax margined at base, and may be 

 tabulated thus, all of our species having entire simple claws : — 



Clypeus separated from the front by a suture. PELIDNOT2E. 



Mandibles externally bidentate at tip. Pemdnota. 



Mandibles not toothed externally. Plitsiotis. 



Clypeus not separate from the front. AREODiE. 



Last joint of tarsi without any inferior prominence. , Cotalpa. 



Pelidnota is represented only by the common P. punctata, a 

 reddish-yellow insect, with three black spots on each elytron ; 

 Plusiotis by the species from the Gila River before mentioned ; 

 Cotalpa by the common G. lanigera, of a pale yellow color above, 

 with a golden reflection, beneath dark metallic green, covered 

 with white hair; C. granicolUs Hald., a smaller, coarsely punc- 



