AMERICAN COLEOPTERA. 173 



becoming wider and forming a conical mass, about as long as the club : 

 the scape is more thickened at tip than in the allied genera, being- 

 more than twice as wide as the 1st joint of the funiculus. 



The tibiae are very strongly toothed on the outer margin, the 1st 

 joint of the tarsi is longer than the 2d, and the 3d is broader and bilo- 

 bed, the front tibise are armed with a strong apical hook. The 2d, 3d 

 and 4th ventral sutures are strongly bent backwards at the margin, as 

 in some Curculionidaej a character not seen in any of the allied 

 genera. 



Our species may be tabulated as follows : 



A. Prothorax narrowed in front: 



Intervals of elytra rough for their whole extent, hairs moderate : 



Thorax very densely coarsely punctured 1. terebrans. 



Thorax less densely punctured 2. obesus. 



Intervals of elytra rough in front, only punctured behind, hairs long; 



Thorax unequally punctured; 3. rufipennis. 



Thorax more sparsely punctured, intervals of elytra less rough. 4. punctatas. 



Thorax strongly punctured, intervals of elytra scarcely gran- 



ulated,even in front 5. simplex. 



B. Prothorax scarcely narrowed in front, head very large : 



Intervals of the elytra slightly rough, pubescence short 6. frontalis. 



1. D. terebrans Lac. Gen. Col. vii, 361. :=2). valeno Lee. Pac. R. R. Explora- 

 tions, xi, Ins. 59. (Ante, p. 149.) 



The synonym belongs to a larger form of this species, found in Cali- 

 fornia and Oregon! 



2. D. oheavLS-^H^i/lurgus obesus Mannh. Bull. Mosc. 1S43, 296; ibid. 1852, 356: 

 D. similis Lee. Pac. R. R. Explor. xi, Ins. 59. 



Alaska and Oregon. A smaller form, only 4 mm. long, occurs at 



Lake Superior and in Canada. 



3. D. TVL&'penms.^ ^fylu)'g^ls rufpennis Kirby, Faun. Bor. Am. iv, 195, fide 

 Mannh. Bull. Mosc. 1853, 238. 



Alaska: the punctures of the thorax are not very dense, and of two 



sizes intermixed. 



4. D. punctatus. — Of the same form as D. terebrans. The erect hairs are mucli 

 longer, the punctures of the prothorax much less dense, and the elytra are 

 roughened only near the base, the intervals being finely and sj)arsely punc- 

 tured behind, without elevated granules. Long. 6 mm. 



One specimen, northern New York. 



5. D. simplex. — Of the same form as the smaller race of D. obesus, but with 

 the thorax more coarsely punctured, the elytra less roughened in front, more 

 obliquely declivous and somewhat flattened behind, with the intervals on the 

 declivity absolutely free from tubercles, and marked only with ranges of pili- 

 ferbus punctures; the sutural stria is much deeper. Long. 4 mm. 



Two specimens from Canada are in my collection. 



6. D. frontalis Zimm. (Ante, p. 149.) 



TRANS. AMER. ENT. SOC. (23) SEPTEMBER, 1868. 



