150 Annals Entomological Society oj America [Vol. IX, 



with the other appendages, occupying a more or less sunken 

 area between the elevated face parts and the first pair of legs; 

 tarsi of the first pair of legs and tips of the second pair of legs 

 adjacent on the meson ; median line always very distinct on the 

 prothorax, weak on the mesothorax and sometimes slightly 

 indicated on the metathorax ; caudal portion of mesonotum and 

 the metanotum depressed adjacent to the wings; wings with 

 their distal margins always strongly raised above the dorsal 

 surface of the body; first pair of wings with their anal angles 

 rounded and opposite the cephalic margin of the fourth abdom- 

 inal segment; second pair of wings visible along entire margin 

 of first wing, but usually almost concealed by the first wing on 

 the third abdominal segment and produced around the anal 

 angle of first wing to the caudal margin of the fourth abdominal 

 segment ; abdominal segments usually with three rows of tuber- 

 cle scars on each side the meson, one row situated laterad of 

 the dorsal medial line about one-fourth the distance between the 

 medial line and the spiracular line, the second row on the 

 dorsum about half way between the first row and the spiracular 

 line, the third row on the ventral surface, not quite half way 

 between the spiracular line and the proleg scars; abdominal 

 segments 8-10 tapering rapidly to form a cone. 



The genus Samia is found in nearly all parts of North 

 America. There are four recognized species in this genus, 

 S. cecropia, reported from the entire region east of the Rocky 

 Mountains, 6". gloveri, from the Rocky Mountain region and 

 Arizona, S. Columbia, from the Northern Atlantic States, and 

 S. californica, from the Pacific States. The cocoons are always 

 fastened by one side to a twig with fibers of silk; the general 

 shape is oval. Cecropia cocoons are large, the largest found in 

 North America, usually at least three inches long with two 

 distinct layers of silk. There are many different shapes and at 

 least two distinct types of cocoons, those with a very loose, soft 

 outer layer giving the cocoon a "baggy" appearance and those 

 firmer on the outside which are seldom more than an inch in 

 width, often only three-fourths, while the "baggy "ones usually 

 reach a width of two inches or even more. No satisfactory 

 explanation has been given for this variation. The cocoons of 

 the other species are similar to those of S. cecropia but smaller 

 and usually firm. The cocoon of S. gloveri may usually be rec- 

 ognized by its external coating of white silk, which is spun first 



