88 Tratis. Acad. Sci. of St. Louis. 



distinctly shorter; abdomen not quite as wide as the elytra. Male with 

 the third and fourth ventrals narrowly and very feebly impressed along 

 the middle, the fifth more broadly and deeply so, the impression atten- 

 nuate anteriorly and not attaining the base, the apex with a shallow, 

 circularly rounded sinus in median third; sixth ventral narrowly and 

 deeply impressed along the median line except near the base, the apical 

 margin with a large and very deep angulate notch, the bottom of which 

 is filled with a broad whitish submembranous area having a transverse 

 or feebly sinuate posterior outline; impressions more coarsely pubes- 

 cent or spiculose. Length 8.8 mm.; width 1.15 mm. Rhode Island 



(Boston Neck; rigidnm n. sp. 



19 — Male with ventrals three to six impressed, the sixth with a narrow and 

 deep emargination. Body parallel, shining, blacli or slightly piceous, the 

 elytra gradually rufesceat posteriorly; legs and antennae as in the pre- 

 ceding species; head parallel and broadly arcuate at the sides, the 

 latter merging gradually into the broadly rounded basal angles, the 

 punctures fine but deep and very sparse; strongly obconic medial 

 joints of the antennae but little more than one-half longer than wide; 

 prothorax broad, but slightly elongate, a little wider than the head, 

 subparallel, the sides becoming straight in the middle; punctures very 

 sparse and only moderately coarse; elytra fully as long as wide, paral- 

 lel and feebly arcuate at the sides, slightly wider and shorter than the 

 prothorax, the punctures like those of the head, fine and very sparse; 

 abdomen nearly as wide as the elytra. Male with the impression of the 

 third and fourth ventrals narrow and feeble, of the fifth wider, deeper 

 and elongate-oval, the apex feebly, broadly sinuate in the middle, the 

 sixth with a large deep triangular emargination about as deep as wide, 

 with its edges glabrous anteriorly, the impressions spiculose as usual; 

 female with the sixth ventral rather small, feebly lobed at tip. Length 

 8.5 mm ; width 1.2 mm. Rhode Island (Boston Neck). 



postremum n. sp. 

 Male with ventrals three and four wholly unmodified; five and six im- 

 pressed, the sixth with a very broad sinus much wider than deep. Body 

 parallel, stouter in form than postremum, polished, black, the elytra 

 gradually rufo-piceous posteriorly as a rule; head subquadrate, the 

 sides parallel and feebly arcuate, the angles rather broadly rounded, 

 the punctures fine and very sparse; antennae stout, the strongly 

 obconical joints oae-half longer than wide; prothorax large, oblong, 

 distinctly wider than the head, but little longer than wide, very feebly 

 narrowed posteriorly from the rounded apical angles, the punctures 

 coarse and very sparse; elytra subquadrate, parallel, slightly shorter 

 and wider than the prothorax, normally convex, rather finely, very 

 sparsely and confusedly punctate; abdomen as wide as the elytra, 

 minutely and densely punctulate. Male with the fifth ventral narrowly 

 and deeply impressed along the middle except near the base, the apex 

 broadly, feebly sinuate toward the middle; sixth with a broader, deep, 

 more anteriorly narrowed impression throughout, the apex with a 

 broad and rather shallow sinus, three or four times as wide as deep, its 

 bottom broadly, very obtusely angulate, the sinus fully half as wide 

 as the segment; female with the sixth ventral obtusely lobed at tip, 



