33 



Hind wings yellowish gray, mottled with blackish outwardly. The fore wings 

 have the costal edge pale marked with black ; the black shading obtains on costa 

 at apical third, and over the whole wing at terminal third extending obliquely 

 downwards and inwards; there are a series of interspacial longitudinal black 

 streaks before the margin, more or less defined. Fringes whitish, dotted with 

 black opposite the ends of the veins, which latter conversely_are whitish. Thorax 

 shaded with yellowish gray behind. Abdomen dark gray. Beneath the wings 

 repeat the markings very distinctly, owing to the strong contrast of the pale 

 ground color with the black markings. Expanse, 82 mm. i 9 . Wells, Elko Co., 

 Nevada." 



The italicized portion of the original description serves to show 

 the points which cause us to regard angrcci as a species distinct from 

 popuH. We do not know the insect at all. 



A. CENTERENSis Lintncf. (PI. VII, figs. 4 and 5.) 



Cossus centerensis Lintner, Can. Ent., IX, 129 (1877) ; Bailey, Can. Ent., XI, i, 

 PI. I (1879) ; Packard, U. S. Ent. Com. Bui!., No. 7. P- 121 (1881) ; Bail- 

 ey, Bull. Dept. Agri. Ent., Ill, p. 49, PI. I (1883) ; Neumoegen & Dyar. 

 Jour. N. Y. Ent. Soc, II, p. 161 (1894); Holland, Moth Book, p. 377. 

 PI. XII, fig. I (1903) ; Wolley-Dod, Can. Ent., XXXVIII, p. 266 (1906) 



Trypanus centerensis Kirby, Cat. Lep. Het., I. p. 861 (1892). 



Bailey and Holland both give well executed figures of this species 

 and we consider any further descriptions superfluous. The larva is 

 found in Populus and an account of the early stages is given at some 

 length by Bailey. 



Hab., Northern States westward to British Columbia. 



In Coll. Barnes, 4 $ S , 2 2 9 , from N. H., N. Y., Chicago, 111. 

 Kaslo, B. C. 



Genus Prionxystus Grote. (Type robinae Peck.) 



Cossus Walker, Cat. Lep. Het. Brit. Mus., VII, p. 1514 (partim) (1856). 

 Xyleutes Packard (non Hubner, 1822) Proc. Ent. Soc. Phil., Ill, p. 388 (1864). 

 Xystus Grote, Am. Phil. Soc, p. 263 (1874) (preocc). 

 Prionxystus Grote, New Check List, p. 63 (1882) ; Bailey, Bull. Dep. Agr. Ent., 



Ill, p. 54 (1883); Kirby, Cat. Lep. Het., I, 867 (1892); Neumoegen & 



Dyar, Jour. N. Y. Ent. Soc, II, p. 163 (1894). 



Sexes dissimilar ; antennae of both sexes pectinate ; palpi upturned, head 

 prominent; prothorax elongate; squammation of thorax very scanty, composed 

 of flat scales ; hind tibiae with two pairs of rather small spurs ; primaries rather 

 pointed, especially in S, secondaries in i concave on outer margin, in 5 well 

 rounded ; venation as in Acossus. 



