30 GEO. H. HORN, M. 1). 



The two specimens examined are the types in the collection of 

 LeConte, both females. The terminal joint of the antennae is equal 

 to the three ])receding. In one of the two specimens the thorax is 

 distinctly longer than wide, the sides feebly arcuate, the other speci- 

 men is larger, thoi-ax as wide as long, the sides arcuate. 



This species occupies an intei'mediate position between plnrijyiinc- 

 tata and the species which follow, being related to the former by the 

 grooved tibia?, and to the latter by the very few setigerous punctures. 



Occurs in Lower California. 



S. opacicollis n. sp. — Piceous brown, shining, antennte and legs mucli 

 paler, head and thorax darker and opaque. Head sparsely punctate. Thorax 

 longer tlian wide, sides very feebly arcuate, lateral margin slightly distinct, sur- 

 face finely scabrous. Elytra striate, strife crenately punctured, intervals slightly 

 convex, the first, third, fifth and seventh with numerous setigerous punctures 

 from base to apex, the ninth with few behind the middle, a few along the lateral 

 margin behind the middle. Body beneath smooth, shining, paler than above. 

 Outer edge of tibiae rounded, not grooved. Length .35 — .40 inch ; 9 — 10.5 mm. 



The antennte are a little longer than half the body, the terminal 

 joint in the male equal to five and the female to three preceding. 



By its very numerous setigerous punctures this species is related 

 to plnrlpuiidafa, but the tibia? are simple, not grooved on the outer 

 edge. 



Occurs in Arizona (Morrison). 



S. rei^pleiidoilN Mels. Proc. Acad. 1845, p. .311.— Piceous, shining, elytra 

 with slight a;neous lustre, thorax reddish yellow, legs piceous or paler. Antennte 

 piceous, scarcely half as long as the body. Head sparsely punctate. Thorax a 

 little longer than wide, sides feebly arcuate, base slightly explanate, surface 

 sparsely finely punctate. Elytra striate, strise finely and closely, but not cren- 

 ately punctured, intervals slightly convex, the first without setigerous punctures, 

 the third and fifth with very few behind the nnddle. others close to the border 

 near the apex. Body beneath nearly smooth, shining. Length .30 inch ; 7.5 mm. 



The antennae are entirely piceous, the terminal joint equal to the 

 five preceding in the male and three in the female. 



In the short diagnosis given by Melsheimer the legs are said to be 

 yellow, but in the more detailed description are pale brown. It is 

 evident that he had immature specimens before him and did not 

 properly discriminate. 



Occurs in the Middle States i-egion. 



S. croceicollis Makl., Acta Fenn. 1863, p. 594. 



Closely related to the preceding species and diflfering in the fol- 

 lowing particulars : 



