XOPcTH AMERICAN I.EPIDOPTERA. 129 



the length of the body. Thorax stout, tlie wings inserted well for- 

 ward ; vestitiire fine, recumbent, forming an indistinct dorsal crest. 

 Abdomen conic, in the S with a small anal tuft ; segments armed 

 with spinules on the hinder edge. Legs comparatively small and 

 weak, the posterior not much longer or stouter than the anterior ; me- 

 dian tibiie with a pair of minute terminal spurs, and posterior with 

 two pairs of small spurs ; tibire otherwise unarmed. Primaries nar- 

 row, outer margin angulated ; apex truncate ; thence excavate to 

 vein 4, where it is produced, and below this deeply indented ; anal 

 angle prominent, produced ; inner margin sinuate ; 12 veined, the 

 venation of the normal type. Secondaries small, outer margin sin- 

 uate, slightly denticulate and somewhat produced on vein lb ; vena- 

 tion of the normal type. The supra-anal })late of the % is elongate, 

 triangnlar, with the hook moderately long, stout and not much 

 curved, obtuse at tip ; the inferior projection about two-thirds as 

 long and acute at tip ; side pieces elongate, rather narrow, with an 

 obliquely rounded tij) ; clasper a long, corneous shank running to 

 the base, produced at about the middle of side piece into stout hook, 

 dilated basally and with a somewhat curved, more slender tij). 



This peculiar genus is readily recognizable ; the ^merinthokl wing- 

 shape, combined with the elongated corneous tongue, the compressed 

 frontal tuft and rather slender abdomen, form a combination not 

 easily mistakable. 



Mr. Butler, in Pap. i, 103, says of the genus : " Seems, excepting 

 in the form of secondaries, to be intermediate in structure between 

 Lophura continua (of Brazil) and Amphlon nessus. It also seems 

 allied to Mimas and Ci/pa, two old world genera of iSmerinthime. To 

 which has it really most affinity ?" To the Smerinthhue, by all odds, 

 I think. 



Maassen makes Deidamia a synonym of Pterogon, showing thus 

 that he knows neither of them structurally. 



There is but a single species in our fauna. 



D. iii»«<'ri|>tiini Harr.,* Cat. Sph. Sill. Journ. .36, 306, Pterogon? ; Wlk., C. B. 

 M. Lep. Het. viii, 100, Thyreiisf ; Clem., Journ. Ac. N. Sci. Phil, iv, 1859 

 137. Deidamia ; Morris, Cat. Lep. 1860, 18, Proserpinus ; Synopsis, 1862, 159, 

 Deidamia ; G. & R., Proc. Ent. Soc. Phil. v. 151, Deidamia ; Bd., Sp. Gen. 

 Het. i, 302, Trichocolon; Grt., Buff. Bull. i. 20; id. ii, 225, Deidamia; Strk., 

 Le)). Rhop. et Het. 112, pi. 13, fig. 8, % , Pterogon ; Butl., Tr. Zool. Soc. Loud, 

 ix, 535; Pap. i, 103, Deidamia ; Maassen, Stett. Ent. Zeit. 1880, v. 41, p. 53, 

 Pterogon; Fernald,* Sphing. 69, Deidamia ; Grt., Hawk Mollis 29, Deidamia. 



TRANS. AMEK. KNT. soc. XV. (17) JULY, 1888. 



