44 PROCEEDINGS OF THE NATIONAL MUSEUM vol. ii4 



distance of several diameters ; frontal carina complete, of low to mod- 

 erate height, often lowest mediall}'^ and abruptly terminated laterally, 

 usually straight or slightly sinuous when viewed from above; vertex 

 behind the carina smooth except for a few scattered punctures. 



Pronotum weakly convex, the features as described in male minors, 

 except that in females the tubercles overhanging the pronotal punc- 

 tures are often more pronounced. Elytra with the same features and 

 varying no more than male minor from the male major. Pygidium 

 more convex, otherwise similar to the males. Ventral surfaces with 

 the pimctures slightly more pronounced, similar to the males except 

 that the last abdominal segment is not narrowed medially. Foretibia 

 short, quadridentate, with teeth larger than in male majors and 

 margin of tibia between the teeth serrate or denticulate; lacking 

 apical conical projection noted on the foretibia of male majors. 



Type. — Unknown to writers. 



Type locality. — "Etats-Unis (Carohne du Sud)." 



Specimens examined. — 1646. 



Distribution. — (See fig. 1, p. 17.) Nebraska, Oldahoma, Texas, 

 and all States east of these except possibly New Hampshire and Maine. 

 No records from Canada. 



Remarks. — ^This species presents interesting problems. Several 

 forms have been described, and because all have similar habits, it 

 has been difficult to decide upon the limit of variability for certain 

 populations. The unicolorous form and the bicolored specimens are 

 considered a single species owing to their sympatric distribution and 

 variable and overlapping morphological characteristics. The form 

 0. floridanus Blatchley is subsequently listed and described as an 

 allopatric subspecies (p. 45). Many of the characteristics of s. flori- 

 danus, such as tuberculate-punctate pronotum and black color, appear 

 separately in populations of s. striatidus, but of the many specimens 

 examined none with a range outside the southeastern coastal plain 

 exliibited all the characteristics of 5. floridanus. This fact coupled 

 with the restricted distribution of s. floridanus would seem to make 

 valid its recognition as a subspecies. 



0. striatulus is the most variable North American species of the 

 genus, but is easily recognized if a male major is in the series. The 

 two long horns on the head, which fit on each side of the pronotal 

 protuberance, the coarsely punctured pronotal disc (tubercles some- 

 times at the anterior margin of the punctures), tuberculate-granulate 

 elytral intervals, and the varied color wliich is never dull black distin- 

 guish the male majors. The male minors and females with the evenly 

 rounded or sliglitly emarginate clypeus, coarsely punctate pronotum, 

 tuberculate-granulate elytral intervals, varied color, and conspicuous 

 setae both dorsall}'' and ventrally can be rather easily separated from 



