NORTH AMKRICAN LEPIDOPTERA. 231 



Can. Ent. i. 48 (50) Cressonia ; Git., BuflF. Bull. i. 24, Cressonia ; Bd.,« Sp. 

 Gen. Het. i. 27, Smerinthns ; Strk., Lep. Ehop. et Het. 53. pi. vii, fig 12 %, 

 13 9; Smerinthus ; But!., Tr. Zool. Soc. Lond. ix. 590, Cressonia; Pack.* 

 Guide 274, Cressonia; Edw.,* Pap. iii. 127, Cressonia; Fernald,* Sphing. 80. 

 Cressonia : Grt., Hawk Moths 36, Cressonia. 



robinsonii Biitl., Tr. Zool. Soc. Lond. ix. 590, Smerinthus; Strk., Lep. Ehop. 

 et Het. 140; Grt., Buff. Bull. iii. 223, pr. var. ; Maasseu, Stett. Ezit. Zeit- 

 1880. V. 41, p. 62, pr. syn. 



9 pallens Strk.. Lep. Ehop. et Het. 54, pi. vii, fig. 14; id. 141, Smerinthus; 

 Grt., Buff. Bull. ii. 150, pr. syn. ; Butl., Tr. Zool. Soc. Lond. ix. .590, an sp. 

 dist.? Maassen, Stett. Ent. Zeit. 1880, v. 41, p. 62, pr. syn. 



Ground color of upper side varying from pale gray to deep fawn color; prima- 

 ries often with a lilac purple suffusion. Palpi darker than other parts of head. 

 Thorax usually with a darker brown line, marking the thoracic crest. Abdomen 

 with the edges of the segments often narrowly paler or darker. Beneath, the 

 forelegs and prothorax are darker than the rest of the under side, which is else- 

 where of the same general color as the upper side. Primaries with a rigid, up- 

 right, transverse line at basal third ; within this, and rather close to it, is another 

 more indistinct line, more nearly perpendicular to the costa, and therefore not 

 quite parallel to the other line. From the costa at outer third a transverse line, 

 much bent at its inception, runs obliquely inward to the middle of the internal 

 margin. Just beyond is another similar line the inclosed space usually somewhat 

 paler than the rest of the wing ; within the first mentioned line is usually a 

 parallel, deeper, suffused shade, which is sometimes wanting and sometimes con- 

 nected with the line, forming a single broad dark baud. Outer portion of wing 

 usually more or less shaded with brown ; in well marked specimens the sp-tce is 

 brown, except a pale costal patch from which a diffuse pale shade runs to the 

 hind angle. The discal spot is bi-own. The inferior portion of median space is 

 darker brown, shading off into the ground color; rarely this darker shade is 

 wanting. Secondaries with two parallel, median, transverse lines, which inclose 

 a usually paler space, the lines preceded and followed by a more or less distinct 

 dusky shade, the inner one sometimes forming a third parallel line. Beneath 

 brown, irrorate, paler at base of primaries, the two parallel outer lines of prima- 

 ries reproduced, preceded on both wings by dusky brown shades. Beyond these 

 lines the secondaries are brown to the outer margiu, the fringes marked with 

 gray lunules; on the primaries the gray subterminal shade of the primaries is 

 reproduced. Expands 2.5 — 3.5 inches; 63 — 88 mm. 



Hab. — Canada to Georgia ; westward to Mississippi, Texas. 



This species is perhaps the most variable of the Snierinthid forms. 

 It varies remarkalDly in size, largely in color, and greatly in the dis- 

 tinctness of maculation. Mr. Strecker's pallens is based on a very 

 pale specimen in which the upper surface is uniformly ochraceous 

 and the transverse lines very narrow. A specimen in my own col- 

 lection has the ground color so dark that all save the basal lines are 

 lost on the primaries. The robinsonii of Mr. Butler is based on an 

 unusually large specimen. 



