OF ARTS AND SCIENCES. 65 



V. 



STUDIES ON TPIE TRANSFORMATIONS OF MOTHS OF 

 THE FAMILY SATURNIIDiE. 



By a. S. Packard, M. D. 



Presented February 8, 1893. 



The larval characters of the members of this interesting group, 

 especially those features which are congenital, tend to show that the 

 family has originated from some spiny group, and most probably, when 

 we take into account the transformations of Aglia tau, from the Cera- 

 tocampidie, although none of the latter spin a cocoon. During the 

 evolution of the group they underwent a change in shape, from a rather 

 long and slender form to a thick heavy body, with a thin integument, 

 the result perhaps of an unusually stationary mode of life. The ima- 

 gines also underwent a process of degeneration, as seen in the atrophy, 

 total or partial, of the maxillae, and in the loss of veins in their very 

 large but weak wings ; though the loss of strength of flight is some- 

 what compensated for by the remarkable development of the olfactory 

 organs, or antennae. 



This family also appears to be a closed type ; viz. none of the 

 higher. or more speciahzed Bombyces appear to have descended from 

 it (unless possibly the Cochliopodid^), the type representing a side 

 branch of the Bombycine tree which late in geological histoiy grew 

 apart, and reached a marked degree of modification, resulting in the 

 possession of adaptive characters which were not transmitted to later 

 forms. It seems probable that the type was a Miocene Tertiary one, 

 which has lingered on in Eastern America (North and South), and in 

 Eastern Asia, as well as in Africa, while it has become nearly extinct 

 on the Pacific shores of North and South America, and in Europe. 



Saturnia (m its restricted sense) the most generalized Genus of its 

 Family. — In the European Saturnia carpini and its allies, and our 

 Pacific coast species, Saturnia mendocino and S. galbina, the larva of 

 the former species having been described by the late Henry Edwards 

 (Proc. Cal. Acad. Sci., Dec. 17, 1877), we have perhaps the most 

 generalized and primitive members of the family. In the larva of 



