98 NORTH AMERICAN 



the first segment, where they are longer, more slender, and slightly inclined 

 inward. Legs short, dark fnsco-piceous, under surface of femora fuscous 

 and much paler ; first joint of posterior tarsi one-half as long again as the 

 second, much shorter than the last, second much longer than the third, fourth 

 very small ; tarsi gradually attenuated toward tip. 



Male. — Posterior edge of the fifth ventral segment emarginate in its mid- 

 dle third, emargination evenly rounded and about ten times as wide as deep, 

 contiguous surface feebly impressed, impression becoming gradually extinct 

 anteriorly; sixth segment deeply sinuate at apex, sinus and apices of equal 

 curvature, the former evenly and rather acutely rounded, and about twice 

 as wide as deep ; seventh evenly and rather strongly emarginate at tip. 



Female. — Sixth segment broadly and very evenly rounded behind. 



Length 2.4-2.9 mm. 



Cambridge, Massachusetts, 46 ; Trenton Falls, New York, 4 ; 

 Detroit, Michigan, 6 ; Batchehwauung Bay, Lake Superior, 2 ; Michi- 

 picoten River, Lake Superior, 4 ; Marquette, Michigan, 4 ; Isle 

 Royale, Lake Superior, 1 ; Fort Garland, Colorado, 2; Lake Quesnel, 

 British Columbia, 9. 



Easily recognized by its very short elytra, large prothorax, and 

 very rough sculpture. As may be seen by the foregoing list of 

 localities, it is very widely distributed, and I can find no perceptible 

 variation of any kind, even in specimens from the most widely sepa- 

 rated regions. 



77. S. gravidlis n. sp. — Form rather robust, sides parallel. Pubescence 

 very short, semi-erect, rather sparse, fine, dark plumbeo-cinereous. Head 

 Large and robust, distinctly more than twice as wide as long; interocular 

 surface nearly flat, twice as wide as the eye ; equally trilobed by the very 

 faint, rounded sulcations ; intermediate surface rather strongly and evenly 

 convex, rising above the general surface ; punctures small, very close, poly- 

 gonal, confusedly coalescent ; ocular lines meeting at less than one length in 

 advance ; antennae distinctly shorter than the width of head, slender, club 

 moderate, dark piceous-brown, basal joint black ; third joint one-fourth as 

 long again as the fourth, fourth and fifth equal, sixth shorter and much 

 more slender than the seventh, eighth equal in width to the seventh, slightly 

 elongated, nearly sub-globular, joints of club very gradually increasing in 

 length, ninth oval and intermediate in thickness between the eighth and 

 tenth, tenth and eleventh of equal width ; maxillary palpi moderate in 

 length, piceous-brown, first joint and base of the second piceo-testaceous. 

 Prothorax robust, arcuately and rather rapidly widening to a point slightly 

 in advance of the middle, where it is three-fourths as wide as the head, and 

 just perceptibly narrower than long ; sides thence moderately convergent 

 and straight; anterior and posterior margins sub-equal in length, the former 

 slightly the more arcuate ; surface distinctly tuberculate near the basal 

 angles, tuberculations widely separated ; also transversely and rather feebly 

 impressed just behind the anterior margin ; punctures rather small, feebly 



