Sphingidae 

 Genus ISOGRAMMA Rothschild & Jordan 



This genus has been erected by Rothschild & Jordan for the 

 reception of the single species which we figure. The learned 

 authors say: "In the shortness of the fore tibia and first segment 

 of the fore tarsus the only species of this genus agrees with 

 the species of Ceratomia, and in the preservation of the pulvillus 

 with CHtenogramma, while it differs from both genera in the 

 fore tibia and the extreme apex of the mid tibia being armed 

 with spines. The spinosity of the tibia is an advanced character, 

 not acquired by Ceratomia, while the pulvillus is an ancestral 

 structure already lost in Ceratomia." 



(i) Isogramma hageni Grote, Plate IV, Fig. 8, $ . (Hagen's 

 Sphinx.) 



This obscurely colored hawkmoth, which is liable to be 

 confounded with some of the species of Ceratomia, which it 

 superficially resembles, may be distinguished at a glance by the 

 slightly greenish shade of the primaries and by the absence 

 of the dark-brown border of the hind wings, which is charac- 

 teristic of all the species of Ceratomia. It occurs in Texas. 



Genus CERATOMIA Harris 



The tongue is reduced in size. The palpi are small. The 

 eyes are small. The tibiae are unarmed. There is no comb 

 of bristles on the mid tarsus, the pulvillus is absent, the 

 paronychium is present. The primaries are relatively large with 

 evenly rounded outer margin. The secondaries are slightly pro- 

 duced at the end of vein i b. 



The species have dissimilar larvae. In the case of amyntor 

 the larva has four horn-like projections on the thoracic seg- 

 ments; in the case of the other two species of the genus the larvae 

 are distinctly and normally sphingiform. 



The tongue-case of the pupa is not projecting. 



(i) Ceratomia amyntor Hiibner, Plate IV, Fig. 6, $. 

 (The Four-horned Sphinx.) 



Syn. quadricornis Harris; ulmi Henry Edwards. 



This common hawkmoth, which may be easily recognized by 

 our figure, lives in the larval state upon the elm. It ranges from 

 Canada to the Carolinas and westward through the Mississippi 

 Valley, wherever its food-plant is found. 



47 



