1916] Classificatio7i oj the SaturniidcB 153 



concealed by first wing on the third abdominal segment and 

 produced below the anal angle of first wing to the caudal margin 

 of the fourth abdominal segment; spiracles usually free, the 

 first and second sometimes partially concealed by the wings; 

 abdominal segments with the three rows of tubercle scars 

 distinct; abdominal segments 5-7 with their dorsal cephalic 

 margins very rarely produced into flange-like plates and these 

 scarcely visible in lateral view, and elevated, longitudinally 

 striate, wavy line between the segment and the transverse 

 conjunctiva; abdominal segments 8-10 with the caudal end 

 seldom produced into a narrow, blunt tip; in ventral view the 

 scars of the anal prolegs usually distinct on each side of the 

 anal plate; cremaster absent. Length, abdomen retracted, 

 32-35 mm., expanded, 40-45 mm.; girth about 55 mm. 



Samia Columbia Smith. — Color usually dark brown to black- 

 ish; face parts slightly elevated; face parts, exposed surface of 

 thorax and dorsal surface of abdomen with fine, determinate, 

 transverse striations, specially marked on the mesothorax, 

 metathorax and face pieces; antennae of male with the stem of 

 the flagellum about one-third the total width of the antenna, 

 and not extending beyond the pectinations, the length of the 

 antenna about two and three-quarters times the width, ending 

 opposite the tips of the first pair of legs; clypeo-labral suture 

 usually distinct; clypeal region strongly elevated, mound-like, 

 above the labrum; labrum variable, its proximal margin con- 

 cave, width at least twice length, the distal margin broadly 

 rounded; maxillae, measured on meson, one-fourth the length 

 of the wings, its mesal length usually greater than greatest 

 width, the surface polished; third pair of legs very seldom 

 visible between the wings; mesothorax with the alar area 

 longitudinally rugose throughout, appearing somewhat polished 

 to the unaided eye; metathorax with a prominent tubercle on 

 each side the meson, a smaller one near each lateral margin, 

 both tubercles reddish at tip; a similar pair usually present 

 each side the meson on the first abdominal segment ; second pair 

 of wings not visible around entire dorsal margin of front wing 

 being covered by the first pair of wings between the first and 

 third abdominal spiracles; abdominal segments with the three 

 rows of tubercle scars present and conspicuous; abdominal 

 segments 5-7 sometimes with indications of a flange-like plate 

 notched at the meson but never extending as far laterad as the 



