no. i. BOMBYCINE MOTHS OF NORTH AMERICA— PACKARD. 265 



[ARCH^OATTACUS Watson. 

 ArchseoaUacus nov. gen., type Attacus edwardsi (White), Proc. Zool. Soc. Lond. 1859, PI. XLVI, fig. 1. 



I am forming this genus to include A. edwardsi (White); A. staudingeri (Rothschild, Nov. 

 Zool., vol. 2, 1S95, p. 36) and probably a new smaller species, as yet undescribed, from Thibet, 

 which M. Charles Oberthur has shown me in his collection. This genus was indicated by myself 

 as a subgenus in the transactions of the Manchester Entomological Society, 1910, and is more 

 closely allied in all its stages as far as known to tbe genus Philosamia (Asian), Drepanoptera 

 (African), and Samia (American), and I have therefore proposed for these two or possibly three 

 species generic rank, with which Mr. Oberthur concurs. Antennae of the female less deeply 

 pectinated than Attacus proper. 



Body as in Philosamia, longtitudinally striped (edwardsi). Pupa (edwardsi) without 



armed ventral processes as in Attacus. Ova much smaller than Attacus; less rounded. Costal 



vein of fore wing separated from the first subcostal by nearly twice the distance as between 



: the second and third equidistant in Attacus; a short spur given off near the apex more abruptly 



than in Attacus proper, making the wing apex slightly lobed. 



The white fascia beyond the vitreous disk in this genus and the three other genera above 

 mentioned curves outwardly toward the apex of the forewing; toward the base in Attacus and 

 Coscinocera. In the figure of edwardsi male in Sonthonnax's Lab. d'Etudes de la Soie, Plate 

 XII, the antennas are much too wide and quite out of all proportion to the actual thing. — 

 J. H. Watson.] 



HYBRID SATURNIHLE. 



Plate LXXXVIII, f. c. d. 



[The Saturniidae have produced many hybrids in captivity. Descriptions of these hybrid 

 larvae are given below, but in the two cases where the parents were of different genera, one of 

 them being CaUosamia prorneihea, the larvae were like promethea.* In one of these cases the 

 promethea parent is stated to be female, in the other no statement concerning sex is made. It 

 seems very possible that these are "false hybrids," which always exactly reproduce the specific 

 characters of the female parent. 



The species of Samia and Saturnia, especially, cross freely in captivity. Thus in Samia 

 the following hybrids have been described : (1) cecropia <? X gloveri 9 ; (2) cecropia <? X rubra 

 9 ; (3) Columbia 3 X cecropia 9 ; (4) rubra cf X cecropia 9 • Special names have been given 

 to these hybrids by Tutt. 



Tropsea luna 3 has been crossed with Actias selene 9 , a fact which may be used in support 

 of the view that Tropsea is a synonym of Actias. 



The hybrids of Saturnia are very numerous and complicated, and have especially been 

 investigated by Dr. M. Standfuss of Zurich, whose truly astonishing collection I have examined. 

 Some of the principal crosses are as follows: (1) pavonia-minor d X spini 9 ; (2) spini c? X 

 pavonia-minor 9 ; (3) pavonia-minor d X pavonia-major 9 ; (4) pavonia-major <? X spini 9 ; (5) 

 pavonia-major 3 X pavonia-minor 9 ; (6) atlantica X pavonia-major. For the last see A. 

 Ebner, Intern. Entom. Zeits., v (1911), p. 158. Several of these hybrids have proved fertile, 

 and so it has been possible to produce a form derived from three different species, or cross back 

 the hybrid with one of the parent species, as follows: 



(1) Hybr. bornemanni Stdfss. (ex pavonia-minor <$ X spini 9 ) s X pavonia-minor 9 . 



(2) Hybr. emilise Stdfss. (ex pavonia-minor <? X pavonia-major 9 ) c? X pavonia-minor 9 . 



(3) Hybr. emilise Stdfss. <? X pavonia-major 9 • 



(4) Hybr. bornemanni Stdfss. s X pavonia-major 9 • This is the hybrid derived from three 

 species. 



(5) Hybr. bornemanni Stdfss. <? X spini 9 ■ 



(6) Hybr. standfussi Wiskt. (ex emilise 3 X pavonia-minor 9 ) S X pavonia-minor 9 • 



1 (Mls5 Soule, however, refers to a "cynthia form" of larva, as well as a " promethea form," obtained from the cross cynlhiatf X promethea 9-] 



