Horn.] OOU [June 20, 



densely punctured, frontal stria slightly interrupted at middle. Thorax 

 with fimbriate margin, surface minutely and very sparsely punctured on 

 the disc, much more densely and coarsely at the sides, and with a row of 

 coarse punctures along the base. Elytra densely punctured at apex, 

 punctured space neatly limited in front, and extending equally densely 

 along the interatrial spaces to base, except a space near the base between 

 the striae 2-4 ; external subhumeral continent with the marginal, internal 

 moderately long, joining the humeral ; first dorsal confused at base ex- 

 tending beyond the middle, second distinct equal to the first, third 

 entirely obliterated, rarely a rudiment at base or a few punctures, fourth 

 dorsal extending to middle, arching at base, joining the sutural which is 

 entire. Propygidium and pygidium coarsely and moderately densely 

 punctured. Anterior tibise finely 6-7 denticulate, middle and third tibias 

 spinulose. Length .10-14 inch; 2.5-3.5 mm. 



The juxta-scutellar impunctured space varies in extent. All the speci- 

 mens agree in the entire obliteration of the third dorsal. This species 

 and rugipennis have a remarkable superficial resemblance, but differ in 

 the structure of the prosternum. 



Occurs from Owen's Valley, California, southward to Cape San Lucas, 

 also in Arizona. 



S. lubricus, Lee. Ann. Lye. V., p. 100 ; Mars. Mon., 1855, p. 410, pi. 

 17, fig. 4G ; rotundifrons, Mars. Mon., 1862, p. 464, pi. 12, fig. 24. 



Oval, moderately convex, black, shining, surface slightly bronzed. 

 Head coarsely and moderately densely punctured, frontal stria inter- 

 rupted at middle. Thorax with lateral margins fimbriate, at sides with 

 moderately broad and well defined space coarsely and densely punctured; 

 punctures slightly stronger at the margins, a narrow basal space punc- 

 tured. Elytra with well defined smooth space, punctures coarse and 

 dense at apical third, extending also to the bases of the interstrial spaces 

 and equally dense ; external subhumeral absent, internal feebly im- 

 pressed continuous with the humeral ; first dorsal confused at base 

 extending nearly to middle, second somewhat longer, third equal to the 

 first, fourth equal to the second, arched at base joining the sutural which 

 is entire and deeply impressed, sutural interspace with a row of punc- 

 tures. Propygidium and pygidium densely, but not very coarsely punc- 

 tured. Anterior tibiae multidenticulate, middle and hindtibne sphmlose. 

 Length .10-14 inch ; 2.5-3.5 mm. 



This is the only species of the present group in which the scutellar 

 space is entirely surrounded by a dense punctuation. The type of 

 rotundifrons, Mars., is before me, and is an exact reproduction of the 

 type of lubricus. 



Occurs in California, especially in the southern portion of the State. 



S. plenus, Lee. Ann. Lye. V., p. 169 ; olidus, Lee. Proc. Acad., 1859, 

 p. 316 ; pratensis, Lee. Col. Kansas, 1859, p. 8. 

 Oval, convex, shining, surface distinctly bronzed. Head convex, 



