1^16] Classification of the SaturniidcB 



141 



5 to 



Genus Tropaea Hiibner. 

 Body usually somewhat depressed; abdominal segments 

 :o 7 distinctly tapering, face parts never elevated above 

 the surface of the body; antennas pectinate throughout, the 

 stem of the fiagellum elevated above the level of the pecti- 

 nations and more than one-third the total width ; invaginations 

 for the anterior arms of the tentorium distinct; eye-pieces 

 both visible; clypeo-labral suture distinct; maxillae, measured on 

 meson, about one-eighth the length of wings; about half the 

 tibias and the tarsi of the first pair of legs and the tips of the 

 second pair of legs adjacent on the meson ; median Hne distinct 

 on all thoracic segments; each mesothoracic spiracle about one- 

 fourth the distance along the caudal margin of prothorax to 

 meson ; mesothorax with a prominent tubercle at base of wings 

 and a slight depression along lateral margin of alar area; caudal 

 part of mesonotum and metanotum not depressed adjacent to 

 wings; wings with their distal margins not elevated above the 

 surface of the body; abdominal segments 5 to 7 with the lateral 

 aspects of the cephalic margins covered with sharp, slightly 

 wavy, transverse ridges with distinct furrows between, the 

 cephalic margin narrowed on the dorsum, the furrows extending 

 dorsad about two-thirds of the distance between the spiracular 

 line and the meson and ventrad less than half way between the 

 spiracular Hne and the meson, the furrows usually concealed 

 when the abdomen is retracted; abdominal segments 8 to 10 

 tapering quickly to form a convex cone-shaped piece; caudal 

 end of body deeply rugose with a sHght concavity containing 

 a circular group of strongly recurved spines, the curved tips 

 all pointing toward the center of the group. 



_ This genus is found throughout the Atlantic States and the 

 Mississippi Valley, and includes a single species in this country. 

 The cocoon is ovoid, thin and "papery" on the outside, with a 

 thin inner layer of loose fibers of silk, but it has no opening 

 at the end with loose fibers of silk closing it, as in Callosamia 

 promethea. The cocoon is usually brown in color, and is found 

 among the leaves on the ground under the food plant. 



Tropaea luna Linnaeus.— Color generally chestnut brown 

 with an irregular white blotch extending between the proximal 

 ends of the antennae; face parts and exposed portion of thorax 

 with fine indeterminate, impressed lines, the first eight abdom- 



