AMERICAN COLEOrTERA. 141 



two, very short, the inner united with the sutural by several larger 

 punctures forming a faint arch. Humeral stria very fine. 



One specimen from Key West, agreeing with all the characters 

 given by Marseul. The species may be found farther north. 



S. seneicollis, Mars. Monog. 1855, p. 424, pi. 17, fig. 56. — Very closely resem- 

 bles S. penn.v/Ivanicus, but may be at once distinguished by the deep groove 

 around the lateral and apical margins of the pygidium. The entire upper sur- 

 face is shining, thorax bronze and elytra blue, with a tinge of green. The ely- 

 tra liave the first and second striss distinctly marked, extending three fourths 

 of the length of the elytra ; third stria short, basal ; fourth extending to middle 

 and arching at base to join the sutural; oblique humeral stria distinct but fine, 

 internal subhumeral obliterated, external very short. Surface of elytra sparse- 

 Ij"- and finely punctured, apical region with coarser punctures extending for- 

 ward in lines to meet the striae, and also more numerously along the suture. 

 Length (from apex of thorax to tip of suture) .20 — .22 inch ; 5 — 5.5 mm. 



This species has already occurred in south-western Texas. 



PLEGADERUS, Erichs. 

 P. nitidus, n. sp. — Oblong, moderately convex, black, shining. Antennae 

 piceous, club paler. Head punctured. Thorax broader than long, narrower in 

 front, sides at middle slightly sinuate, disc divided by a transverse sulcus into 

 two unequal portions, sparsely and rather finely punctured the anterior portion 

 rather more densely punctured than the posterior and more densely and 

 coarsely near the lateral groove. Margin rather coarsely punctured and more 

 densely in front. Lateral groove not attaining the basai margin. Elytra 

 sparsely punctured but more densely and coarsely than the thorax. Proster- 

 num bicanaliculate, median convex portion broadly interrupted and with a 

 patch of silken hairs. Meso- and metasternum very finely and sparsely punc- 

 tured, side pieces and first abdominal segment coarsely punctured. Legs 

 piceous, anterior tibiae gradually broader and very finely denticulate. Length 

 (from apex of thorax to tip of elytral suture) .09 inch; 2i ram. 



Three specimens from Nevada, one of which was sent me by Mr. 

 Henry p]dwards, of San Francisco. 



This is our largest species and may be distinguished at a glance by 

 the shining black color of the thorax. 



P. fraternus, n. sp. — Oblong, moderately convex, piceous black, shining. 

 Antennre i)ieeo-rufous, club paler. Head coarsely and rather densely punc- 

 tured, but densely on the vertex. Thorax slightly broader than long, sides 

 rounded in front, parallel behind the transverse groove. Disc unequally divi- 

 ded by a well defined transverse impression, anterior portion smaller; surface 

 shining, sparsely punctured, slightly more densely on the anterior portion. 

 Basal margin with a row of large rather closely placed punctures. Lateral 

 groove attaining the basal margin, thickened margin coarsely punctured. Ely- 

 tra coarsely and closely punctured. Prosternum bicanaliculate, median por- 

 tion divided near apex by a broad transverse groove, silky pubescent at bottom. 

 Anterior portion of middle of prosternum triangular coarsely punctured, sternal 

 Bide pieces and first abdominal segment very coarsely punctured. Anterior 



TRANS. AMKR. ENT. SOC. (19) SKI'TEMBER, 1870. 



