1910] Barnes and McDunnough—S phingide of North America 191 
monumental work, we might state that the trinomial system 
of nomenclature here adopted is based on the fact that all species 
are more or less liable to geographical variation; taking the first 
geographical race described as the name for the whole species, 
the names of the different racial forms are merely added to this 
name without intervention of the term var. Thus chersis oreo- 
daphne would be equivalent to chersis var. oreodaphne, and, since 
the first described race is as much a geographical variety as all 
others, the name chersis chersis must be used to indicate the typi- 
cal race. Variations within the limits of a single race are termed 
forms; thus we have P. modesta imperator f. t. kwnzet which 
indicates the summer form (kunzei) of the imperator race (Ariz.) 
of P. modesta Harris. 
In conclusion we might state that we are thoroughly in sym- 
pathy with the system of nomenclature advocated so ably by 
Rothschild & Jordan. The making the first species mentioned 
under a given generic name the type of that genus may seem at 
first sight rather radical, but it at least possesses the advantage 
of being absolutely infallible, besides saving an enormous amount 
of misspent labor in searching through ancient and musty vol- 
umes, as is involved under the “restriction” principle, a prin- 
ciple only capable of being carried out with any fairly assured 
certainty of success when one has the entomological literature 
of the world at one’s command. Surely a system which will 
assure a lasting stability and uniformity in our only too involved 
entomological nomenclature should be hailed with acclamation 
by all those who have the true welfare of entomology at heart; 
like a dose of purging medicine it may cause considerable dis- 
comfort for a time, but if the result will be to free our successors 
from all the difficulties we are at present contending with, then 
let us submit with cheerful spirits to any such slight personal 
inconvenience as it may entail. 
List of Sphingidae north of Mexico. 
Subfamily ACHERONTIINE. 
Tribe ACHERONTIICE. 
Genus Herse Oken. 
(1) H. cingulata Fabr. N. Y. to Tex. 
ab. decolorata Hy. Edw. 
