418 Annals Entomological Society of America [Vol. XI, 



Atreus plebeja Fabr. 



Color chestnut brown, often marked with black or darker brown 

 blotches in various places; body surface polished except the head, pro- 

 thorax and parts of the mesothorax which are irregularly sculptured; 

 abdominal segments finely, but rather sparsely punctate excepting 

 along the cephalic portions of the segments; median pair of tubercles 

 on labrum longer than broad, rounded at the tip, the lateral ones shorter 

 and somewhat pointed; maxillary loop about 12 mm. long, not extend- 

 ing as far caudad as the antenna of either sex, usually as far as the 

 prothoracic legs; scar of caudal horn very distinct, smooth and pol- 

 ished, usually with shallow radiating furrows; cremaster with the 

 proximal half rugose, the remainder smooth and polished, its length 

 about 2.5 mm., ending in a pointed tip, with occasional indications of 

 bifurcation. Length of pupa 40-45 mm.; greatest width 10 mm. 



Genus Sphinx L. 



This genus is very closely related to Protoparce, the main 

 difference in the pupae being in the maxillary loop, which is 

 never strongly arched in Sphinx, but closely applied to the 

 ventral surface of the body in most species, or slightly elevated 

 in others. The body is typically sphingiform, with the labrum 

 at the cephalic end of the body and partially visible in ventral 

 view. The antennae have the surface more or less roughened 

 with minute rounded tubercles, and are transversely ridged, to 

 correspond with the segmentation of the adult. There is a 

 noticeable difference in the length of antennae in most species. 

 Nearly all of the species show annulets on the dorsum, although 

 only on the cephalic segments in some species. The movable 

 segments have two spiracular furrows, the inner one deep and 

 pocket-like, the outer shallow, both with carinate edges, less 

 than 5 mm. long, and never extending ventrad of the spiracle. 

 The scar of the caudal horn is always present, usually easily 

 distinguished by a smooth area, while the remaining surface of 

 the segment is punctate. Many species have a prominent 

 depression just caudad of the scar. The cremaster is always 

 triangular, longer than broad and bifurcate at the tip in most 

 species. According to Rothschild and Jordan this genus includes 

 thirty species and twenty of these occur in North America. 

 Some of these species are confined to the region west of the 

 Mississippi. Of the eastern species, it has only been possible to 

 obtain pupae of six. Three of these I have reared many times: 

 5. chersis, S. kalmice, and 6*. drupiferarum. Of the other species 

 live pupae were purchased and one or two allowed to emerge. 



