124 BOMBYCIDiE. 
stituted it is of very great extent; but the most 
cursory glance suffices to show that its contents are 
far too heterogeneous to accord with the notion we 
now form of a genus. Without a full series of spe- 
cimens, or more accurate descriptive details than we 
now possess, it would be impossible to make a satis- 
factory revision of the Saturniae with a view to 
their distribution into consistent genera. But there 
are certain characteristic features affording a basis 
for this distribution to which it may be worth while 
briefly to advert. The hinder margin of the poste- 
rior wings is either regularly rounded, produced 
into an acute angle, or drawn out into a long nar- 
row tail. As these distinctions are connected with 
others of an equally important although less obvious 
kind, they may be adopted for the establishment of 
three primary groups. Of these the first is by far 
the most extensive, including the great mass of the 
species, such as S. atlas, hesperua, cecropia, &c. 
To S. atlas and its congeners, distinguished by 
their great size, development of the palpi, large 
vitreous spaces on the disk of the wings, &c., we 
would assign the name II?/alopkora,'* a term nearly 
corresponding to Porte-mirroir of the French and 
Spiegeldrager of the Dutch. The great majority of 
the middle-sized and smaller species, in which the 
vitreous space is supplanted by an ocelliform spot 
(the British and continental species are examples), 
might retain the old name Saturnia; but even in 
the section thus restricted, there is room for further 
* From uaXos, viirum, and (ptou./ero. 
