90 CASEY 



feebly arcuate; abdomen strongly convex, polished, feebly and 

 sparsely punctate. Length 12.5 mm.; width 6.0 mm. Califor- 

 nia (Calaveras Co., — at an elevation of 2,300 feet). 



sanfordi Blaisd. 



The form which I have identified as abdonimalis displays 

 very Httle sexual difference in the form of the prothorax, while 

 in integer this difference is more pronounced than in any other 

 known species of the genus. In the definition of robnsta, as 

 given above, I have made use of all the characters published by 

 its author, assuming as the type the specimen numbered " i " 

 (Rev. Ten., p. 296) and abandon the species, represented by an 

 assumed cotype in the LeConte cabinet, described under this 

 name in my previous revision (Col. Not., II, 1890, p. 375). The 

 species represented by this latter specimen undoubtedly has a 

 completely margined prosternal process and may possibly be 

 unconsciously included above, among the forms from abdonii- 

 nalis to 7'tigosa in the table ; it is probable that the process is not 

 apically margined in the true robnsta, although the author 

 records nothing concerning a character of which he subse- 

 quently made constant use in Eusattus. The sculpture of ro- 

 bnsta departs to a very remarkable degree from the usual fine 

 sparse punctures of this first group of the genus, but is suggested 

 in the coarser punctuation of costulata, which is a markedly 

 aberrant species. The species described by Blaisdell under the 

 name sanfordi (Ent. News, VI, p. 235) probably belongs in 

 this group, although rather discordant in habitat; it is described 

 above from the published characters. 



Group II. — Type opaca. 



The probably even more numerous species of this group, 

 reproduce the general form and sculpture of their more stren- 

 uous relatives of the abdominalis group, but are alwa3^s very 

 much smaller in size, including in fact some of the smaller 

 species of the genus. They inhabit also a distinctl}^ different 

 region, being virtually confined to the southern Sierras and ad- 

 jacent regions, not occurring, so far as known to me, very near 

 the coast; more definite localities when recorded, will be stated 

 below. Those known at present, representing probably but a 

 moderate proportion of all actually existing forms, may be thus 

 distinguished among themselves : — 



