THe Insect FAUNA OF THE GENUS CRATAEGUS 1089 
THEOBALD, FRED V. The app'e blossom weevil. Jn The insect and other 
allied pests of orchard, bush, and hothouse fruits, and their prevention 
and treatment, p. 104-110. 1909. 
WeLLHOUSE, WALTER H. Xanthonia villosula Melsh. injuring forest 
trees. Journ. econ. ent. 12:396-397. 1919. 
Memoir 52, Studies in Pollen, with Special Reference to Longevity, the fourth preceding number in this 
series of publications, was mailed on March 9, 1922. 
