BOMBYCID^. 293 



alhifrons Smith (Fig. 225) is known by the costa being white 

 on the outer two-thirds. It feeds on the oak, to which it is oc- 

 casionally destructive. Mr. Riley (American Entomologist, 

 vol. i, p. 39) describes the larva as being of a "bluish white 

 ground-color, marked longitudinally Avith yellow bands and 

 fine black lines, with the head and a hump on the eleventh seg- 

 ment either of a light coral or dark flesh color." It generally 

 elevates the end of the body. It pupates during the last of 

 September, the moth appearing about the middle of April, in 

 the vicinity of Chicago. 



Platypteryx, a small geometra-like moth, with its broad fal- 

 cate wings, seems a miniature Attacus. Its larva is slender, 

 with fourteen legs, and naked, with several little prominences 

 on the back, and the tail is forked like 

 Cerura. The pupa is enclosed in a co- 

 coon among leaves. P. genicidata 

 Walker, and Dryopteris rosea Grote, 

 represent this interesting group. We 

 also give a rude sketch, traced from 

 Abbot's drawings, from the advanced 

 sheets of the Harris Correspondence, of 

 an undescribed species of Dryopteris 

 (Fig. 226, and its larva). Doubleday Fig. 32g. 



states that the moth is rose-colored, with a few red dots in the 

 yellow portion of the hind wings. 



The Chinese silk- worm, Bomhyx mori Linn., has white falcate 

 fore wings, while the hind wings do not reach to the tip 

 of the abdomen, and the antennae are well pectinated. The 

 larva is naked, rather slender compared with those of the next 

 group, and cylindrical ; the second thoracic ring is humped, and 

 thei'e is a long horn on the tail. It is three to three and a half 

 inches long. It is of an ash}' or cream color, but "in almost 

 every batch of Avorms there will be seen after the first moult 

 has occurred, some dark colored, which, at the first glance, 

 appear to be a distinct species," but Captain Hutton, of India, 

 shows that "so far, however, are the}- from being a mere pass- 

 ing variety that thej^ are actually types of the original species, 

 and merely require to be treated according to the established 

 rules of breeding in order to render them permanent and 

 healthy." 



