662 William T. M. Forbes 



ently transitional to the Uranioidea. Many authors consider the Hemi- 

 leuca group also a distinct family, some including and some excluding 

 Automeris. It is certaintly transitional between the Citheroniidas and 

 Saturniidas. 



Key to the genera, imago 



1. Mj of fore wing distinctly stalked, with R-stem (figs. 420-422); antennae 



pectinate with simple apex, or simple. 



2. Small species, expanse under 75 mm.; middle discocellular short and oblique 



inward. 



3. Inner margin of fore wing longer than outer margin; two white discal 



dots, or none; northern species shaded with crimson on the hind wing 



(fig. 421) C. 3. Adelocephala. 



3. Inner margin shorter than outer margin, (fig. 422), except in forms with 

 a single large white discal dot; our species with more red on fore than 



hind wing, if there is any C. 4. Anisota. 



2. Large species, expanse over 75 mm.; middle discocellular oblique outward 

 in general direction. 

 3. Mid-discocellular much shorter than lower discocellular, and straight 

 (fig. 419), rudiment of stem of M 1+2 running into M 2 ; It, present; palpi 



larger C. 1. Citheronia. 



3. Middle discocellular long and angled (fig. 420), base of M 1+ , running to 



the angle; R 2 lost; palpi smaller C. 2. Eacles. 



1. Mi free; upper discocellular much shorter than' middle discocellular, and 



nearly transverse (fig. 415) . . S. 2. Automeris. 



1. M! free; upper discocellular nearly longitudinal, and much longer than middle 

 discocellular, which may be obliterated (figs. 413, 414). 

 2. 3d A of hind wing more than half as long as 2d A (fig. 416). 



S. 1. Hemileuca. 

 2. 3d A of hind wing rudimentary. 



3. Hind wings long-tailed S. 3. Tropaea. 



3. Hind wings rounded. 



4. Abdomen with small raised tufts of hair S. 7. Philosamia. 



4. Abdomen with smooth hair. 



5. Cells closed by a fine vein passing through a transparent spot. 



, S. 4. Telea. 



5. Cells open. 



6. R 2 preserved; sexes strongly dissimilar (fig. 413).. S. 5. Callosamia. 

 6. R, lost, sexes alike S. 6. Samia. 



Key to genera, larva 



1. A single pair of long spines on thorax C. 4. .Anisota. 



1. Two pairs on thorax, and caudal horn much longer than the subdorsal ones 

 on remaining segments of abdomen (fig. 423). 



2. Secondary hairs conspicuous C. 2. Eacles. 



2. Secondary hair microscopic. 



3. Spines strongly flattened and silvery C. 3. Adelocephala. 



3. Spines cylindrical. 



4. Five principal spines short and blunt, the others rudimentary. 



S. 5. Callosamia. 



4. All spines long and rough or branched . C. 1. Citheronia. 



(Also young of Eacles and Adelocephala). 



