358 SCOLYTID^. 



[LeConte. 



3. X. scabricollis Lee. Trans. Am. Ent. Soc. 1868, 158. 



District of Columbia, one J^; Mr. Ulke. This species has entirely the 

 form and sculpture of X bivittatus, except that the prothorax instead of 

 being punctured behind the middle, is covered with flat granules, produced 

 by anastomosing rugae, and the front part is as rough as in the 9 of X bi- 

 vittatus. The stri* of punctures on the elytra are also deeper, and the color 

 is different; the head and elytra are piceous, and the prothorax dull, ferru- 

 ginous; the antennae and legs, as usual, are yellow testaceous. Length 3.5 

 mm. ; .14 inch. 



4. X. politus Say, Journ. Ac. Nat. Sc. v, 356 (Bostrichus); ed. Lee. 

 ii, 318; Lee, Trans. Am. Ent. Soc. 1868, 159. 



Massachusetts to Kansas and Georgia. Length 3.3 mm.; .13 inch. 



I have received specimens from Mr. J. A. Lintner, as depredating upon 

 maple trees. Easily known by being more hairy than the other species, 

 with the interspaces of the elytra sparsely punctured, so that the rows of 

 punctures appear confused. I observe no sexual dilierence in the specimens 

 before me, and the species may readily be separated as a distinct genus, by 

 any one who will avail himself of the characters in the antennal club, 

 which I have pointed out above. 



X. unicolor Eichhoff, Berl. Ent. Zeitschr., 1871, 136, is unknown to 

 me, but seems to be allied to X politus. 



Group TIL Xyleborl. 



The essential character of this group is that the club of the antennae is 

 entirely corneous, and not articulated (m the inner surface; on the outer 

 surface it is also corneous, except towards the distal end, where it is ob- 

 liquely truncate; the truncate surface is pubescent and sensitive, and has 

 three concentric or transverse sutures, which indicate the other joints of 

 the club. The scape of the antennae is elongate, and the funicle usually 

 distinctly o-jointed, though in some species there appear to be but four 

 joints. The tibiae are dilated, more or less serrate, and spinose on the outer 

 margin, with the apex obtusely rounded, and the inner angle not very 

 strongly unguiculate. The tarsi are slender; fourth joint small, fifth nearly 

 as long as the others united; claws strong, divergent, simple. 

 Sensitive surface of antennae concentrically annulated... XYLEBORUS. 

 Sensitive surface of antennae with straight, transverse 



sutures DRYOCCETES. 



XYLEBORUS Eichhoflf. 



A. Body stout, cylindrical; declivity of elytra oblique, scarcely flattened; 

 funicle of antennae with four distinct joints; tibiae finely serrate on the dis- 

 tal half of their length, and rounded at tip. 



Declivity of elytra without elevated granules 2. 



" " with a few acute " 1. tachygraphus. 



2. Cylindrical, rather elongate 2. pyri. 



Very stout, oval cylindrical 3. obesus. 



