66 NORTH AMERICAN 



rather finely and very irregularly punctured ; near the inner basal angles 

 the punctures are widely isolated, the interspaces flat and highly polished, 

 elsewhere, and especially toward the inner apical angles, they are closely 

 compressed, often coalescent and somewhat larger. Abdominal segments 

 decreasing extremely gradually in width, first two as wide as the contiguous 

 elytra ; surface feebly and evenly convex, coarsely, closely, and evenly 

 punctulate, the punctures becoming much finer and feebler toward the tip ; 

 transverse carinae tricuspid, cusps distant, middle ones short and finely 

 aciculate, lateral nearly as long, but very wide, rounded at tips. Legs 

 fuscous, rather long and slender; first joint of posterior tarsi two-thirds as 

 long again as the second, and as long as the last, joints two to four uniformly 

 and rather rapidly decreasing in length. 



Male. — Posterior edge of fifth ventral segment just perceptibly emarginate 

 in its middle third, emargination evenly rounded, and excessively feeble, 

 contiguous surface feebly flattened throughout anteriorly ; sixth segment 

 broadly sinuate at apex, sinus feeble, evenly rounded, five to six times as 

 wide as deep ; seventh segment transversely and feebly emarginate at apex, 

 teeth very short. 



Female. — Unknown. 



Length 2.5 mm. 



Waverly, Massachusetts, 1 ; Cambridge, Massachusetts, 1. 



The antennae are missing. This species, although resembling 

 placidus very closely, is, I think, distinct, because of the differences 

 to be observed in the structure of the palpi and elytra. 



37. S. simplex n. sp. (Crotch MS.). — Form moderately robust. Pubes- 

 cence exceedingly short, sparse, and fine, setiform, cinereous. Head rather 

 large, scarcely twice as wide as long ; interocular surface nearly flat, slightly 

 more than twice as wide as the eye, equally trilobed by the sulcations which 

 are scarcely visible ; closely, rather coarsely and evenly punctate ; ocular 

 lines meeting at one and one-half lengths in advance ; antennae moderately 

 slender, as long as the width of head, basal joint black, remainder piceous- 

 brown, club large and prominent ; third joint one-third as long again as the 

 fourth, fourth and fifth equal, sixth and seventh equal and shorter, seventh 

 thicker than the sixth, eighth short and thicker than the seventh, joints of 

 club increasing in length, last joint elongated, acuminate at tip ; first joint 

 of maxillary palpi and base of the second flavo-testaceous, remainder pale 

 piceous-brown. Prothorax widest before the middle, where it is four-fifths 

 as wide as the head, and slightly narrower than long ; sides thence rather 

 feebly convergent posteriorly and strongly sinuate ; anterior margin shorter 

 and more arcuate than the posterior, the latter nearly transverse ; surface 

 feebly and transversely impressed just behind the anterior margin, and 

 faintly tuberculate at each side near the base ; rather finely, variolately, 

 closely, and somewhat irregularly punctured, interspaces very narrow, flat, 

 shining, and minutely reticulated ; canaliculation irregular, shallow, begin- 

 ning before the middle, and extending to within one-fourth the length from 

 the posterior margin. Elytra at base very slightly narrower than the head, 



