226 CALIFORNIA ACADEMY OF SCIENCES. 



alluded to above, are apparently all distinct from those here 

 brought to notice. F'llum differs in the coloration of the 

 antenn^B and in the sexual characters; concolor decidedly in 

 coloration of the entire body; the (Bdeagus, however, is ap- 

 parently similar to that of hicolor; Salvini appears to be 

 closely allied to versicolor, but as no ligula is described in 

 alluding to the male sexual characters,' and as the elytra 

 appear from the figure to be longer and broader, and the 

 apical angles of the prothorax much less pronounced, the 

 two species are probably distinct, more especially in consid- 

 eration of the very different faunal regions involved. Oh- 

 scurus SiTid plceohts are very distinct in color; hrevipennis and 

 umbra differ altogether in structure. Exiguus Er. differs 

 radically in coloration. 



Color appears to be a very constant character, as it is 

 practically the same throughout large series of several spe- 

 cies which I have before me. 



ORUS Cas. 



This genus, and the closely related Leptorus, constitute a 

 group differing remarkably from Scopseus and Scopseodera 

 in the structure of the intercoxal portion of the prosternum. 

 In Orus the posterior edge of the prosternum is more swol- 

 len than in Leptorus, and the median portion is, posterior- 

 ly, elevated into a longitudinal ridge which becomes the 

 lower edge of the intercoxal lamina. 0. lounctatus Cas. and 

 the species here described are the only known representa- 

 tives of this genus in the United States.'^ 



^— The ligula is present in all the species of this genus, but, j)roba- 

 bly only before copulation, is securely held within the long angular cleft of 

 the seventh segment, and is only pushed down and out of the cleft, so as to 

 be plainly visible, after sexual connection has occurred. 



^. — By a very regrettable error it was stated by me (Bull. Cal. Acad. 

 Sci. I, p. 315) that the ligula in Orus is bicuspid. One of the very minute 

 teeth was in all probability hidden under a particle of dust, as the appear- 

 ance in the specimen examined was undoubtedly that of a bicuspid ligula; 



