THE ENTOMOLOGIST. 
Vou. XXV.] MAY, 1892. 
(No. 348. 
NOTE ON GENERIC CHARACTERS IN THE 
NOCTUIDA. 
By Jonn B. Sara. 
Tr will be admitted, I think, that there are no characters, 
structural or otherwise, that are of uniform systematic value in 
all the orders of insects. It will be further admitted, I think, 
that characters of the very highest value in one order, family, 
tribe, or genus, may be of scarcely specific importance in another. 
The question as to what characters are sufficient to authorize a 
genus will be decided by each student for himself, and much in 
accordance with habit and with the surroundings in which he is 
placed. It is not intended, therefore, to suggest anything like an 
arbitrary value for characters, but simply to discuss certain of 
them as to their relative importance and usefulness. A character 
is useful for large divisions in proportion to the amount of 
variation it undergoes, and in proportiofi as the changes are 
sharply defined. A seemingly unimportant character may by its 
constancy be of the highest systematic value. I instance, in the 
Coleoptera, the division of the large sub-family Harpaline, into 
unisetose and bisetos, according as there are one or two supra- 
orbital setigerous punctures. . 
In the Noctuide one of the best characters for generic division 
is in the eyes—whether they are naked or clothed with short 
hair; a single hair arising at an angle of each facet. The 
character is absolute; there is never a doubt as to whether an eye 
is hairy or naked, and I have seen no intermediate forms. No 
species is known to me in which this character is variable, and no 
case is known to me where otherwise nearly-allied species are 
separated by this character. All Leucania, all T’eniocampa, and 
ail Mamestra, for instance, have hairy eyes. Besides, the 
possession of hairy eyes seems to carry with it an absence of 
certain other characters. None of the hairy-eyed genera have 
the tibie spinose, and none have a heavy armature to the fore 
tibia. In some there is a short terminal spine, and there may be 
ENTOM.—maAY, 1892. L 
