230 JOHN B. SMITH. 



hairy, forming a slight, usually discolored crest, which divides near 

 the base in the form of a j^ ; in the female this is much less distinct 

 and often concolorous. The abdomen is long, slender and conic in 

 the % ; stouter, more nearly cylindric in the $ . The male also has 

 minute anal tufts. The legs are moderately stout, subequal in length, 

 the median pair rather the longest. The tibiie are all densely cov- 

 ered with fine short sjnnules, the anterior clothed outwardly with 

 rather long, dense hair; median tibia with a pair of medium sized 

 spurs at tip, posterior with two pairs. Primaries with apex acute, 

 outer margin rounded, sinuate, sometimes a little dentate, hind angle 

 prominent, inner margin sinuate ; eleven veined ; not differing to any 

 extent from its allies. Secondaries rather evenly rounded, the mar- 

 gin entire, or only slightly dentate. 



The supra-anal plate of the male narrows rather rapidly and forms 

 a rather long flattened hook slightly bent and obtusely rounded at 

 tip. The inferior spur is short, not more than half the length of the 

 superior hook. The side pieces are broad, the superior margin 

 straight, the inferior rounded and gradually approaching the supe- 

 rior at the tip, where it forms a somewhat acutely rounded angle. 

 From the middle of the superior margin arises a stout, somewhat 

 curved corneous process with an obtuse tip and serrated inferior 

 margin. 



This is certainly one of the most remarkable and strongly charac- 

 terized of the Smerinihid genera. The antennal structure is unique 

 among the American forms, as is also the shape of the palpi. The 

 frenelum is wanting altogether in the female, and reduced to a mere 

 rudiment in the male. Its affinities with the Saturniidpe are there- 

 fore marked, and consequently I place this genus at the extreme end 

 of the series. 



There is but a single species thus for described in our fauna. It 

 forms Clemens' Group II of Smerinthiis, and Clemens also noted the 

 peculiar antennal structure without giving it the value it merited. 

 I pointed out its bearing in Soc. Ent. ii. No. 1, and in Ent. Am. iii. 

 p. 2. 



C juglan«Iis S. & A.,* Ins. Ga. i. 57, pi. 29, l^phinx ; Hiib., Saml. i. 171, Amor- 

 pha : Verz. 141, Polypti/chus ; St. Farg. AServ. Enc. Meth. x. 441, Smerinthus; 

 Harr.,* Sill. Jouru. .36, 291, Smerinthus; Wlk.,» C. B. M. Lep. Het. viii. 247, 

 Smerinthus ; Emmons,* Nat. Hist. N. Y. Ins. pi. 45, fig. 9, ? Bonibyx ; Harr.,* 

 Inj. Ins. Flint ed. 328, Smerinthus; Clem.,* Jour. Ac. N. Sci. Phil. iv. 1859, 

 185, Smerinthus; Morris,® Syn. 1862, 213, Smerinthus ; Lint.,* Pr. E. S. Phil, 

 iii. 668, Smerinthus: G. & R., Pr. E. S. Phil. v. 161 and 186, Cressonia ; Sanb., 



