125 



sembles those of certain species of Saturniidae and it is quite probable 

 that they had a common ancestor, although the Bombycidae are un- 

 doubtedly more generalized. The only species in America is Bom- 

 by.v niori Linnaeus. 



SuPERFAMiLY NOTODONTOIDE A 



The families included here never have the entire labial palpi ex- 

 posed, but a very small triangular or polygonal area is sometimes visi- 

 ble just caudad of the labrum. Some genera of Geometridae have the 

 prothoracic femora exposed, while the epicranial suture is present in 

 some of the members of each family. Although the larvae of Geomet- 

 ridae are easily recognized and are very readily distinguished from 

 those of the Notodontidae, the pupae show much closer relationships, 

 and it is difficult to draw a hard and fast line between the two fami- 

 lies. The three families included here have probably had a common 

 ancestor, and although the Dioptidae retain the epicranial suture they 

 must be considered the most specialized, as both Geometridae and 

 Notodontidae show more generalized characters in some of their gen- 

 era. The following table may be used to separate the families of 

 Notodontoidea: 



a. Antennae never extending beyond the caudal margin of the wings ; 

 dorsum of abdomen never with a prominent hooked seta on each side 

 of the meson of segments 7-10. 



b. Maxillae usually more than three fifths the length of the wings, if 

 not, then the caudal end of the body with hooked setae, or 

 the spiracles of the third abdominal segment concealed by the 

 wings and those of the sixth segment farther ventrad than those 

 of the other segments ; prothoracic femora often exposed ; a deep 

 furrow usually present on the dorsum of the abdomen between 

 the ninth and tenth segments ; caudal margin of mesothorax never 

 with a row of deep pits with smooth tubercle-like areas between. 



Geometridae. 

 bb. Maxillae seldom exceeding three fifths the length of the wings, if 

 so, then the caudal margin of the mesothorax with a row of deep 

 pits with smooth, elevated, quadrangular tubercle-like areas be- 

 tween them ; or with the entire body surface coarsely punctate ; 

 abdominal spiracles of the third segment never concealed by the 

 wings, and those of the sixth never farther ventrad than the re- 

 mainder ; prothoracic femora never exposed ; a furrow never 

 present on the dorsum of the abdomen between segments 8 and 9 

 except in Datana, where the cremaster is of the type shown in 

 Figure 112 Notodontidae. 



