162 j(3URNAL NeVv YoRK EnT. SoC. [Vol. II. 



C. populi Walker. 



1856 — Cossus populi \\! A-LKKK, Cat. Brit. Mas., pt. VII, p. 1515. 

 1882 — Cossiis aitg7rzi Bailey, Papilio, Vol. II, p. 93. 



Collar and head yellowish gray, thorax partly black. Fore 

 wings with nearly white ground shaded with blackish, with black 

 and reticulated lines, those crossing the center of the wings most 

 distinct. Hind wings yellowish gray, mottled with blackish out- 

 wardly. Expanse, 60—80 mm, 



Habitat, Nevada, Hudsons Bay. 



C. ore Strecker. 



1893 — C^JJiz/j tJ/r Stkecker, Proc. Acad. Nat. Sci. Phil., p. 282. 



Closely similar to C. populi but the lines more reticulated, less 

 strigose, giving the fore wing a mottled appearance. Otherwise 

 the species are alike. Expanse, 55 — 75 mm. 



Habitat, The Pacific northwest. 



C, perplexus Neunmgen S^ Dyar. 



\'^(:)'},— Trypanus peiplexiis Neumcegen & Dyar, Journ. N. Y. Ent. Soc, 

 Vol. I, p. 31. 



Ash gray ; reticulations becoming obsolete, irregular and 

 branched; median and sub-terminal lines remain. Secondaries 

 unicolorous, pale cinereous, sub-translucent. Expanse, t^T) mm. 



Habitat, Colorado. 



C. mucidus Hy. Edwards. 



1882 — Cossus mucidus Hy. Edwards. Papilio, Vol. II. p. 126. 



Reticulations converted into dense transverse strig^e, the 

 fore wings all obscured by blackish shading except the basal costal 

 half where ground color appears, sordid white. Secondaries sordid 

 white, minutely strigose, appearing pulverulent. Expanse, 36 — 

 40 mm. 



Habitat, Arizona. 



Genus Prionoxystus Grote. 



1882 — Prloiioxysitis Grote, New Check-list, p. 63. 



1874 — \Xystiis Grote, Proc. Amer. Phil. Soc, Vol. XIV, p. 262. 



Synopsis of species. 



Wings opaque, secondaries of r^ partly orange .... robiniae. 



Secondaries of 9 ^'so orange tinted ..... var. quercus. 



Wings sub-hyaline, no orange macmurtrei. 



