LECONTE ON EOCKY MOUNTAIN COLEOPPERA. 475 



Gkoup II: — trifaria. 



The episterna of the metathorax are more than one-half longer than 

 wide. The elytra are elongate-oVal, and the humeri are rounded and 

 indistinct, without humeral angle. The outline differs according to 

 species, as will be seen by the table. The prosternum also varies in 

 form. The prothoracic side-margin is wide in trifaria and Rathvoniiy 

 but narrower in purpurata and carhonaria. In the last-named, the hind 

 angles of the prothorax are obtuse, and the dorsal punctures are only 

 on the 2d interspace; in the other three, the sides of the prothorax are 

 strongly sinuate, and the hind angles are rectangular and prominent. 

 There are also punctures on the 3d, 5th, and 7th interspaces, or on the 

 3d and 7th. 



Two species inhabit the Alpine Eocky Mountains, one the Sierra 

 Nevada of California, and One Kamtschatka and the islands of Alaska : — 



Hind angles of prothorax prominent rectangular 2. 



Hind angles of prothorax obtuse ; 3d interspace of elytra with four or five 

 punctures behind the middle ; prosternum flattened at tip, finely 

 margined; color black, antennae and legs dark brown; much smaller 



than the others of this group 7. carhonaria. 



2. Elytra elongate-oval, slightly wider behind, purple, 3d, 5th, and 7th 



with a few punctures behind the middle ; prosternum lanceolate at tip, 



not margined ; prothoracic side-margin narrow. . 4. purpurata^ n. sp. 



Elytra oval, less elongate, 3d, 5th, and 7th interspaces interrupted by 



large punctures ; prosternum margined ; side-margin of prothorax 



broad ; color black 5. trifaria, n. sp. 



Elytraoval, less roundedat thebase, 3d and, 7th interspaces interrupted 

 by smaller punctures ; 5th without punctures ; prosternum not mar- 

 gined at tip ; side margin of prothorax wide ; color black , G. Ratlwoni. 



Group III: — Mannerheimii. 



The species of this group are wider and flatter than those of the pre- 

 ceding, and the elytra are less rounded at base, so that the humeri are 

 indistinct, but not wanting ; the basal fold is slightly bent, and makes 

 a feeble angle with the side-margin, but by no means so obvious as in 

 the following group, and the sides are not parallel, but rounded. The 

 prosternum is flattened at tip and margined, and the side-margin of the 

 prothorax is obviously narrower than in the following groups ; the sides 

 are but feebly sinuate towards the base, and the hind angles, though 

 rectangular, are small and not prominent. There are four or five small 

 dorsal punctures on the 3d stria or adjacent to it. 



Antennae and legs black , 8. Mannerheimii. 



Antennae and legs testaceous 9. Esclisclioltzii. 



Group IV. 



The species of this group are more numerous than those of the other 

 groups united, and may be readily known by the basal fold of the elytra 



