280 Annals Entomological Society of America  [Vol. VII, 
Genus Citheronia Hubner. 
Face-parts and appendages not at all elevated; body surface 
not roughened with spines; eye-pieces both present; invagina- 
tions for the anterior arms of the tentorium small but distinct; 
clypeo-labral suture present; labrum a little wider than long; 
maxillae, measured on the meson, about two-fifths the length 
of the wings, but little longer than the greatest width, tri- 
angular in outline; tips of the tarsi of the first and second 
pair of legs meet obliquely on the meson; median line distinct 
on all thoracic segments; mesothorax with a few minute tuber- 
cules at the bases of the wings; metathorax with a prominent 
oblong tubercule or plate, irregularly sculptured at the sides, 
on each side the meson, extending more than half the width 
of the segment and nearly its whole length; cephalic margins 
of abdominal segments 5 to 7 produced into thin, plate-like 
ridges; spiracular line curved slightly ventrad; cremaster 
short and bifurcate at tip. 
This genus is found principally east of the Mississippi 
and consists of two species, C. regalis and C. sepulchralis. 
Specimens of the latter were not available for study. The 
pupae of C. regalis have a peculiar odor somewhat resembling 
laudanum. 
Citheronia regalis Fabricius. Color dark brown, almost 
black; body surface usually polished, occasionally roughened 
with indeterminate transverse striations; antennae in both 
sexes with the length more than four times the greatest width 
and reaching about half way along the exposed portion of the 
second pair of legs; face parts with a slightly raised line on each 
lateral margin of the clypeus extending cephalad from the 
proximo-lateral margins of the labrum to the proximal ends of 
the antennae; labrum variable, five-sided, pointed at the 
distal end; maxillae much longer than broad, the proximal 
margin sinuate; prothoracic spiracle with elevated margins, the 
cephalic margin forming a prominent rounded ridge; meso- 
thorax with a small tubercule on each side the meson on the 
caudal half of the segment, a tubercule scar laterad of each 
tubercule and in line with it, and a smaller tubercule near the 
caudal margin of the alar area on each side; abdominal seg- 
ments 2 to 7 with a row of punctures near the cephalic margin, in 
