101 
[Packard. 
tidae, the Zygaenidae, the Arctiidae, the Platyplericidae, the Lasiocam- 
pidae and the group represented by Bombyx movi. But I now feel lit- 
tle doubt but that the Sphingidae arose from early generalized forms 
resembling Aglia tau or its progenitor, and our American Cerato- 
campidae. There are several families comprised within the group, 
or superfamily of Bombyces, and quite recently I have been led to 
change my earlier views as to the position of the families. Both 
from their larval characters and the venation of the imagines 1 am 
now inclined to believe that the Notodontidae stand at the base of 
the Bombycine series ; and that they have more or less directly de- 
scended from the Noctuidae. The Lasiocampidae, instead of, as I 
have always supposed, being the lowest group, stand above or on one 
side of the Attacidae and near the Liparidae. The Notodontians, 
Ceratocampidae and Attacidae (including the subfamily Hemileucini) 
all possess but three branches of the median vein ; the Lasiocam- 
pidae with four branches of the same vein, should be associated 
with the Liparidae, and their ontogeny entirely confirms this view. 
The Bombycidae (Bombyx movi ) , Platyptericidae and Psychidae form 
another branch of the Bombycine shrub or tree ; the Cochlidiae 
(Cochliopodidae) another, and the Arctians and Lithosians another. 
On the other hand, the Sphingidae, Sesiadae and Thyrididae form 
a group by themselves, and should be placed between the Agaris- 
tidae together with the Castniadae, and the Hesperian butterflies. 
These families cannot possibly be arranged in a regularly ascend- 
ing series, but seem to form a phylum resembling a scrawty shrub 
or tree, sending branches both upwards and downwards, in no very 
determinate way. The groups represented by the Sphingidae may 
have evolved independently of the group represented by the Zygae- 
nidae and Arctiadae together with the Liparidae and Lasiocampidae. 
But that the Attacidae and Ceratocampidae, with the Notodontidae 
should be regarded as the more synthetic, generalized forms seems 
highly probable, and at least constitutes an admirable working 
theory, explaining many doubtful questions; and by considering 
the Notodontians as the oldest and most generalized group of all, 
and regarding them as originally derived from Noctuid-like forms 
(not the Noctuidae. themselves) , the phylogeny of the great group of 
Bombycine and Sphingid moths seems likely to be in some degree 
cleared up. 
It is to be observed, however, that besides the Notodontians, 
the Bombycidae ( Bombyx mori and allies, certain other species by 
