62 Journal of Entomology and Zoology 
primary 2 mm., secondary 1.2mm. The cornicles are black, imbi- 
cated, cylindrical, somewhat larger near the base, the outer margin 
straight, the inner margin as illustrated (Figure 1, W. corn.). The 
length 0.10 mm., greatest width 0.05 mm. The cauda and anal 
plate are black and as illustrated (Figure 1, W. cauda). 
RELATIONSHIP—This species has been carefully checked with 
Aphis reticulata Wilson, A. oregonensis Wilson, A. hermistonii Wil- 
son, A. tridentatae Wilson, A frigidae Oestlund, and Aphis arte- 
miscola Williams occurring in Oregon on Artemisia tridentata, and 
does not agree with any of them or other closely related species. 
Host—The species occurs in dense colonies on the apical twigs 
of old man or California sage, Artemisia californica Less. 
LocALItTy—In Laguna Canyon one-half mile above Laguna 
Beach, California. 
DATE OF COLLECTION—July 13, 1921. 
CoTYPES—The above description was made from a series of 
cotypes consisting of ten slides and over one hundred mounted indi- 
viduals. The cotypes are in the author’s collection. 
The species is named after Dr. Wm. A. Hilton, Professor of 
Zoology, Pomona College, under whose supervision, inspiration and 
energy a most wonderful type of biological instruction is being 
given each summer at the Laguna Beach Laboratory. 
Figure 1.—Aphis hiltoni n. sp. 
A. Apterous viviparous female; A. tub., body tubercles of 
apterous female; i, prothoracic; ii, front abdominal; iii, posterior 
abdominal; A. corn., apterous cornicle; A., cauda, apterous cauda 
and anal plate; At. t., apterous tarsus; A. ant., apterous antenna; 
W, wings; W. ant., antenna of winged female; W. corn., cornicle of 
winged female; W. cauda, cauda and anal plate of winged female; 
W. tub., body tubercles of winged female; i, prothoracic; ii, front 
abdominal; iii, posterior abdominal. 
