—3° 



metathorax being distinctly though slightly wider in front, and gradually 

 narrowed behind. The femora are not spinose and the spines of the an- 

 tennae are never long. The antenna- are longer than the body in ^J\ 

 the prothorax is very densely punctured with a posterior medial channel 

 and dorsal cicatrices. In Q the antennae are shorter and the prothorax 

 coarsely punctured with a medial and two dorsal callosities. The species 

 are separated as follows: 



Body uniformly finely pubescent; 



Both angles of 3d and 41b joint of antenna 1 spinose procerum. 



Ouier angles only spinose simplicicolle. 



Body irregularly pubescent, with spots of coarser and denser hair; 



Pubescence mottled irregular atomarium. 



Pubescence uniform, fulvous rufulum. 



Sparsely pubescent, elyira very coarsely punctured before the middle, with an irre 

 gular transverse paich ot white pubescence at the middle taeniatum. 



R. procerum Lee. Proc. Ac. Phil. 1859, p. 88. 



Length 37.5 mm. = 1.5 inch. Hah. New Mexico, Cal. 



R. simplicicolle 1 laid. Proc. Ac. Phil. Ill, p. 151; Lee. Journ. Acad. Nat. 

 Sci. Phil. ser. 2, 11, p. 1 2 ; pulverulentus Hald. Trans. Am. Phil. Soc. X, p. 32; Lecontei 

 Dej. Cat. 3d ed. p. 352; Chev. Journ. of Ent. I, p. 243. 



Length 44 mm. = 1.75 inch. Hab. United Stales. 

 The two species above mentioned are very close, and separable only 

 by characters given in the table. The species of this and the succeeding 

 genus are founded on structural differences, in which the family Ceram- 

 bycidae is so rich. In the present and in other instances these differences 

 are so slight as to indicate that the species arc either of very recent ori- 

 gin or are now tending to coalesce. We fail however to find intergrades 

 which would justify us in uniting the species and merely caution the 

 student that the table must be followed very literally to correctly identify 

 specimens. R. aperarium, White, = one of the above species. 



Since the above was in type, Dr. Horn writes as follows: -Alter 

 examining my series, I can not separate procerum and simplicicolle, ami 

 would advise their union under the former name. The arrangement of 

 the antennal spines is an illusory and evanescent character. " 



R. atomarium Drury, 111. 11, 1773, lnd - •- P- 93> t- 4L f- 6; Lee. J. A. P. ser. 2, 

 11, p. 177; marylandieus Fab. Syst. Ent. p. 179; Oliv. Ent. IV, 70, p. 6, t. 1, f. t;; 

 multicolor L. ed. Gmel. I. 4, p. 1857 ; pulverulentus De G. Ins. V, p. 118, t. 14, f. 12. 



length 22- 31 mm. = .88 — 1.22 inch. Hab. Middle and Southern States. 



R. rufulum Maid. Trans. Am. Phil. X, p. 32. 



length 22— 28 mm. = .88 — 1. 15 inch. Hab. Middle States. 



These are again closely related. The fulvous color will distinguish 

 rufulum as well as the uniform pubescence: atomarium being darker in 

 every specimen we have seen. 



