182 JOHN B. SMITH. 



The male of this species is always smaller, more yellow ; the pri- 

 maries more pointed, outer maro;in almost rigidly oblique. In the 

 9 there is a subdued gray shade, the wings are broader, and the 

 outer margin is more convex. The species is a very distinct one, 

 most nearly allied to gordius, with which it agrees perfectly in tibial 

 armature as well as general habitus. Its yellow secondaries, lacking 

 all but a trace of the central band, and the minute, concolorous dis- 

 cal spot, as well as general ground color of primaries are distinctive, 

 and render the species easily recognized. 



The genitalia of the S while on the same general plan as in 

 gordius, yet differ obviously. The side piece is shorter and broader, 

 the clasper is equally stout, broad, concave, but both the angles are 

 jjroduced into long processes the lower pointed at tip and longer, the 

 upper with a rounded tip. 



The species has been frequently raised in the vicinity of New York 

 on willow, but no description has been made, and I have been unable 

 to get hold of any preserved specimens of the larva. This lack in 

 our knowledge of Sphinx larva ought to be soon filled. 



The species is very rare. 



S. albescens Tepper, Bull. Bkln. Ent. Soc. iv, 1, pi. fig. 3, Sphinx. 



Head light gray ; anteunse white above, dark gray beueath ; collar and shoulder 

 covers whitish gray, the latter heavily edged with black iuwardly. Dorsum of 

 thorax deep blackish gray. Abdomen gray, with a black dorsal line edged with 

 gray at the sides, laterally banded with white and black ; beneath uniform dark 

 gray, with a black ventral line. Legs gray. Primaries gray, shaded with cine- 

 reous white along the costa for about half of the wing ; a rather heavy black, 

 apical line, and one near outer margin, the first shaded inwardly and the last 

 outwardly with whitish gray; between these lines and the light costal field are 

 several black streaks; under side gray, powdered with white along the costa and 

 outer margin ; the black apical line is reproduced, and there is a wavy dark line, 

 double at inner margin, and bordered outwardly with whitish gray. Secondaries 

 white at base, followed by a narrow black band, then a narrow white one, both 

 drawn to a sharp point at anal angle; beyond this is a heavy black band shaded 

 with gray towards exterior margin ; under side much as above, but the bands 

 and shadings are not so heavy. Fringes of all wings gray. Expands 2.75 in. ; 

 70 mm. 



Hub. — Colorado. 



Mr. Tepper distinguishes this species from vashtl Strk., by the dark 

 dorsum of thorax and the form of the bands on secondaries, which 

 are angulated opposite the anal angle. This latter is an evanescent 

 character, and only the dark thorax remains to distinguish the two. 

 I have not seen any intermediate specimens. This species forms a 



