172 Mr. A. S. Packard on Aglla tau. 



EXPLANATION OF THE TLATES. 

 Platk X. 



Fi(;. 1. r!<athiiyocans fra(jUis, $, from the leftside. Nat. size. Botli 

 the logs of the secoud pair are tigined, to show their inequality. 



Fig. 2. Rostruui of the same. Enlarged. 



Fig. 3. The caudal swnmmerot of another specimen^ from above. X 3. 



Fig. 4. A leg of the fourth pair of another specimen. X 4. 



Fig. 5. An abdominal appendage of the second pair of anotlier specimen. 

 X 5. 



Plate XT. 



Fig. 1. Psathyrocnris fragilis. Mandible. X U. 



Fig. 2. First maxilla. X 0. 



Fig. 3. Second maxilla. X 9. 



Fig. 4. First maxillipede. X 9. 



Fig. 5. Second maxillipede. X 9. 



Fig. 6. Third maxillipede. X 4-5, 



[To be continued.] 



XXIII. — Aglia tan, a connecting-link hetiveen the Cerato- 

 campidjE and 8aturniida3, and the Type of a new Suhfamily, 

 Agliinffi. By Alpheus S. Packard. 



]n tl)i.s European Bombycine motli wc have a most interesting 

 I'orni surviving side by side with Satiirnia, wliich seems to 

 be ihe most generalized form of its family. Aglia appears 

 to be a Ceiatocampid in its earlier larval stages, the cater- 

 pillar in its final stage, however, and the moth being closely 

 related to the Saturnians. It seems quite reasonable to 

 suppc.ee that the Saturnians have directly descended from a 

 form like Aglia, and we could scarcely expect a clearer 

 demonstration of the origin of one family from another by 

 direct genetic descent. 



"J he transformations of this form, originally figured in 

 L^u],onchel and Guen(?e's ' Iconographie ' * (torn, ii.), have 

 been more fully elaborated by ]\Ir. Poulton f. 



Having received, through the kindness of Dr. Heylaerts, a 

 young larva of Aglia tau in its third stage, I have been able 



* Cuen^e states that, after attaining its full size, " elle ee retire a la 

 surface de la terre, entre des mousses et des dc^bris de v^g^taux qu'elle 

 attache avec de la .«oie, et elle s'y change en une chry.salide grosse, courte, 

 d'un brun fc net? saupoudr^ de grisAtre, et dont I'auus est termiut^ par uu 

 fai.'ceau de pointes recourb^es." 



t Trans. Ent. Soc. London, 1888, pp. .OSB-oGS, pi. xvii. figs. 1-7. 



