LeConte.] 



HYLUBGINI. 385 



1. D. terebrans Lac, Gen. Col. vii, 361 ; Zimm., Tr. Am. Ent. Soc. 



1868, 149 ; Scolytus ter. Oliv., Ent. 78, p. 6 ; pi. 1. f. 6; D. valens Lee, 

 Pacific 11. R. Expl. and Surveys, Ins. 59 ; Chapuls, Mem., Soc. Roy. Liege, 



1869, 91. 



Canada, Georgia, Oregon, California. The specimens from the Pacific 

 slope are larger, and the punctures of the prothorax are rather smaller and 

 more dense, but these differences do not seem to me worthy of specific 

 distinction. Some specimens from New Hampshire and Canada have the 

 prothorax more sparsely punctured, almost as in the next species, from 

 which they are only distinguished by the shorter hairs of the elytra. 

 Length 5.2-8 mm ; .2-. 32 inch. 



2. D. similis Lee, Pac. R. R. Expl. and Surveys, Ins. 59. 



Oregon ; five specimens. I have incorrectly cited this species as a syn- 

 onym of D. obesm, from which it differs in having the aspeiities of the 

 elytra continue on the declivity. The tibiae are armed, as in the preceding, 

 with three acute teeth on the outer side near the tip, but the prothorax 

 is less densely punctured, and the elytral hairs are longer ; the back part of 

 the head is less densely punctured. Length 4.5-6.5 mm.; .18-. 25 inch. 

 \ A smaller and somewhat more elongate form occurs in Canada, Texas 

 and Colorado, but I do not think it capable of being separated as a distinct 

 species. Length 4.2 mm. ; .165 inch. 



3. D. ruflpennis Kirby, Fauna Bor. Am. iv, 195, {Hylurgus); Mann., 

 Bull. Mosc. 1853, 238 ; Hylurgus obesus Mann., ibid. 1843, 296 ; ibid. 1852, 

 356. 



Alaska, Canada, Anticosti. I can perceive no difference between the 

 specimens sent me under the names cited above. It is only to be distin- 

 guished from the preceding by the declivity of the elytra smoother and 

 more shining, and almost without asperities ; and by a slight difference in 

 the punctures of the prothorax, which are of unequal size. The dorsal 

 line of the prothorax is sometimes narrow and elevated, sometimes obsolete. 

 Length 6 mm.; .24 inch. 



4. D, punctatus Lee, Tr. Am. Ent. Soc. 1868, 193. 



New York ; three specimens. Very similar to the preceding, but the 

 back part of the head is nearly smooth, or feebly punctulate ; the punctures 

 of the prothorax are larger and less dense, and the declivity of the elytra 

 less shining, and very slightly asperate. Length 6 mm. ; .25 inch. 



5. D. simplex Lee, Tr. Am. Ent. Soc. 1868, 173. 



Canada ; two specimens. Much smaller, with the prothorax compara- 

 tively wider and shorter, and more densely punctured. The elytra are 

 mare shining, and more strongly and sparsely punctured on the declivitj'-; 

 the head is sparsely but deeply punctured behind, and in front is densely 

 granulate as usual. Length 4 mm. ; .16 inch. 



If I have failed to indicate more strongly the differences between these 

 species, it is because they are not distinguished by any prominent 

 or definite characters ; and the student, who may have difficulty in identi- 



PROC. AMER. PHILOS. SOC. XV. 96. 2w 



