31 



Ips pilifrons Sw. is entirely distinct from engelmanni in its larger size, with the 

 strial punctures very coarse, close and usually quadrate, the frontal tumulus 

 still less elevated, with its cephalic face more oblique, longer, and clothed with 

 extremely dense, short, orange to brownish hairs, resembling the pile on velvet. 

 Engelmanni has variations in punctuation, depth of striae and in the stoutness of 

 the third declivital tooth. Ten specimens were dissected, representing all 

 variations, but all were females. The male is thus far unknown. This species 

 is found in the same sticks with tridens and, probably through the wandering of 

 the autumn-feeding adults, even in the same tunnels during the winter. 



The egg-tunnels were not distinguished from those of tridens. 



Host trees: Picea engelmanni, and probably also Picea canadensis. 



Distribution : Known to us from the Selkirks and Rockies of central British 

 Columbia and from Alberta. 



> 

 Ips yohoensis, n. sp. 



A species with the pronotal and elytral characters of tridens Mannh., but 

 distinct by the characters of the front. The front is very finely and very densely 

 granulate and finely pubescent on the cephalic half, slightly but distinctly 

 transversely elevated behind the epistoma, which is broadly triangularly 

 impressed medially, immediately in front of the elevation, the epistomal margin 

 and the median impression bearing long yellow hairs; the elevation more 

 evidently pubescent than the remainder of the granulate part of the front, 

 with a trace of a smooth median line. The punctuation of the pronotum is 

 usually coarse and close; the elytral striae are usually deeply impressed and 

 coarsely punctured with sparser interstrial punctures nearly as large as those of 

 the striae. The male has the front somewhat more strongly granulate and the 

 third declivital tooth usually somewhat longer and more evidently capitate. 



Variations in the size of the punctures and in the depth of the striae are 

 found. The median line is in some individuals smooth, shining, sulcate from 

 the epistomal impression to the vertex, and guarded on each by a small tubercle 

 at the summit of the epistomal elevation. A considerable number of our 

 specimens have the front entirely or almost entirely free of pubescence. They 

 were taken from the same sticks as the typical series and are probably abraded. 



Host trees. Picea engelmanni and probably P. canadensis. 



Distribution. Known to us only from the Yoho valley, British Columbia. 



Ips hunteri, n. sp. 



Very closely allied to I. interruptus Mannh. in size and sculpture, from 

 which it differs most noticeably by the regularly impressed elytral striae, and 

 the feebly granulate first and second elytral interspaces. 



The front of the head is convex, opaque, densely granulate with coarser 

 granules intermixed, closely hairy; the club with the first two sutures bisinuate. 

 The pronotum about as wide as long, narrowly rounded in front, slightly wider 

 at hind angles (this character variable); rather finely and densely asperate in 

 front, moderately, not closely punctured .behind, more closely and coarsely on 

 the sides. The elytral striae narrow, regularly, distinctly impressed, the sutural 

 striae deeper; the strial punctures small and close; the interspaces finely, 

 uniseriately punctured, somewhat confused and granulate near the declivity, 

 the punctures of interspaces 1 and 2 granulate behind but hardly so on the basal 

 half; the declivity coarsely punctured, not closely, with four spines, the third 

 stout, capitate and acute in the male, more slender and less distinctly capitate 

 in the female. 



Described from a series of about 180 specimens collected by Prof. S. J. 

 Hunter, at Creede, Colo., 8,844 ft. 



