124 ILLINOIS BIOLOGICAL MONOGRAPHS [124 



the last two thoracic and first eight abdominal segments are modified 

 into verricules or thick bunches of short stiff setae. Other scoli are 

 normal. Three species (grotci, juno, and tricolor) have not been seen. 

 Pseudohazis hera is included in the following synopsis of the species of 

 Hemileuca because the writer was unable to distinguish between speci- 

 mens of the larvae labeled with this name in the United States National 

 Museum and those of H. electra. 



a. Verricules alpha of mesothorax each surrounding a seolus which 

 arises from its center and makes the verricule conspicuously differ- 

 ent from those of the metathorax. 

 b. Secondary setae numerous, about half as long as scoli and often 

 as long as verricules. H. neumoegenii 



bb. Secondary setae when present sparse and short. 



c. Dorsal abdominal verricules yellow or light brown, always lighter 

 in color than the scoli. 

 d. Body with pale areas conspicuous, more extensive than dark 

 areas. PL. nevadensis 



dd. Body very dark, pale areas confined to minute dots. 



H. maia. var. lucina 

 cc. Dorsal abdominal verricules as dark in color as the scoli, usually 

 dark brown or black, at least at tip. H. maia 



aa. Verricules of mesothorax similar to those of metathorax, not sur- 

 rounding scoli. 

 b. Secondary setae numerous, subequal to dorsal verricules in length. 



H. electra 

 Pseudohazis hera 

 1)1). Secondary setae sparse, much shorter than verricides. 



H. hualapai var. oliviae 



Pseudohazis. Whatever the family arrangement in Saturnioidea, 

 Pseudohazis and Hemileuca must be placed together for they are very 

 similar. The difference given in the synopsis is not a good one (altho 

 it seems to hold for all species except Pseudohazis hera of the north 

 Pacific states) but I am unable to improve on it at present. P. hera 

 may be separated from the other species by the numerous white dots at 

 the bases of the secondary setae and is thus a typical Hemileuca. In 

 P. eglanterina most of the setae are light in color but the body and 

 verricules are a dead black. The verricules of P. shastaensis are light 

 in color at base and tipped with black, the body color varying in different 

 individuals. 



Automcris. The caterpillar of the Io moth (A. io) is well known 

 and its poisonous spines are rather notorious. The variety fuscus Lu- 

 ther, also found in the Eastern states, has the scoli much smaller, leav- 



