NORTH AMERICAN I>ERIDOPTERA. 129 



the lenti'th of the body. Thorax s^tout, the wiiiirs inserted well for- 

 ward ; vestiture fine, recumbent, forniing an indistinct dorsal crest. 

 Abdomen conic, in the % with a small anal tuft; segments aiMned 

 with spinules on the hinder edge. Legs comparatively small and 

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

 dian tibiae with a pair of minute terminal spur.s, and posterior with 

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

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

 vein 4, where it is pi'oduced, 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 plate of the S is elongate, 

 triangular, 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 nan-ow, with an 

 obliquely rounded tip ; 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 tip. 



This peculiar genus is readily recognizable ; the Smerinthokl wing 

 shape, combined with the elongated corneous tongue, the compressed 

 frontal tuft and rather slender abdomen, form a combination iKjt 

 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 

 Lophnra continua (of Brazil) and Ampluon nessus. It also seems 

 allied to Mima.^ and Cypa, two old world genera of Smerlnthina'. To 

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

 I think. 



Maassen makes Deidamla a synonym of Pterogon, showing thus 

 that he knows neither of them structurally. 



There is but a single species in our fauna. 



I>. iimi'ripttiin Han-.,* Cat. Spb. Sill. Journ. 36, 306, Pterogon? ; VVlk., C. B. 

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

 137. Deidamia; Morris, Cat. Lep. 1860, 18, Prose r pintis ; Synopsis, 1862, 159. 

 Deidnmia; G. .4; R., Proc. Ent. Soc. Phil. v. 151, Deidnmia ; Bd., Sp. Gen. 

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

 Lep. Ehop. et Het. 112, pi. 13, fig. 8, I , Pterogon ; Butl., Tr. Zool. Soc. Lond. 

 i.x, .535; Pap. i, 103, Deidamia ; Maa.ssen, Stett. Ent. Zeit. 1880, v. 41, p. .53. 

 Pterogon; Fernald,* Spbing. 69, Deidamia; Grt., Hawk Mot lis 29, Deidamia. 



TRANS. AMER. KNT. soc. XV. (17) JULY, 18S8. 



