126 ILLINOIS BIOLOGICAL MONOGRAPHS [126 



bb. Scoli alpha of abdominal segments 1 to 6 conspicuous, about 

 as long as thoracic legs. 

 c. Body uniformly and closely tuberculate, stripes faint. 



A. stigma 

 cc. Body irregularly and rather sparsely tuberculate ; stripes con- 

 spicuous. A. consularis 



Thauma and Hylesia. No specimens of these genera were available 

 for study. 



SUPERFAMILY SPHINGOIDEA 



The Sphingidae, the only members of this superfamily, include some 

 of our largest caterpillars. The variation in structure, while not great, 

 is, according to Forbes (1911) sufficient to enable the different genera to 

 be easily identified. His synopsis of the genera and discussion of the 

 species are of great value to anyone with larvae to determine. The fam- 

 ily characters are as follows : 



Head usually smaller than prothorax, usually partially retractile, 

 shorter in dorsal than in ventral portion, always more or less narrowed 

 above ; head in Lapara high and conical above, much higher, tho no 

 wider, than body; setae of head minute and numerous, present on all 

 parts except labrum and mouth parts ; front reaching less than half the 

 distance to vertical triangle ; labrum variously notched. Body cylin- 

 drical, plump ; secondary setae present on prolegs but rare or absent 

 on body ; primary setae reduced or wanting ; when present, kappa and 

 eta distant, eta farther dorsad than kappa and almost as high as spira- 

 cle ; segment 8 bearing a slender horn in most genera ; when reduced, a 

 scar or corniculum marks its location except in Lapara. Prolegs present 

 and large, set close together, bearing biordinal crochets arranged in a 

 mesoseries. Anal prolegs flattened laterad, forming, with the suranal 

 plate, a triangular pyramid. 



RHOPALOCERA 



The butterflies seem to have been separated from other Lepidop- 

 tera at a very remote period. They have been specialized in all stages 

 along entirely different lines. The larvae seem to have separated from 

 the Microlepidoptera before the time when kappa and eta became adja- 

 cent on the abdomen. 



Scudder's "Butterflies of the Eastern United States and Canada" 

 is at present the authority on all stages of Rhopalocera. So many ento- 

 mologists have no access to a copy of this beautiful but expensive work, 

 however, that it is considered worth while to cover the group so far as 



