128 
Psyche 
[April 
Franklin, H. J. 1912-13. The Bombidse of the New World. 
Trans. American Ent. Soc., Vol. 38, pp. 177-486, Vol. 38, 
pp. 73-200, pis. 1-22. 
Frison, T. H. 1916. Note on the Habits of Psithyrus variabilis 
Cress. Bull. Brooklyn Ent. Soc., Vol. 11, pp. 46-47. 
1917. Notes on Bombidse, and on the Life History of 
Bombus auricomus Robt. Annals Ent. Soc. America, 
Vol. 10, pp. 277-286, pis. 23, 24. 
1918. Additional Notes on the Life History of Bombus 
auricomus Robt. Annals Ent. Soc. America, Vol. 11, pp. 
43-48, pi. 3. 
1921. Psithyrus laboriosus Fabr. in the Nests of Bumble- 
bees (Hym.). Canadian Ent., Vol. 53, pp. 100-101. 
1923. Systematic and Biological notes on Bumblebees 
(Bremidse; Hymenoptera). Trans. American Ent. Soc., 
vol. 48, pp. 307-326. 
Howard, L. 0. 1918. An Unusual Bumblebees’ Nest (Hym.). 
Ent. News, Vol. 29, pp. 114-115. 
Plath, O. E. 1922a. Notes on Psithyrus, With Records of Two 
New American Hosts. Biol. Bull., Vol. 43, pp. 23-44, pi. 1. 
1922b. Notes on the Nesting Habits of Several North 
American Bumblebees. Psyche, Vol. 29, pp. 189-202. 
1924. Miscellaneous Biological Observations on Bumble- 
bees. Biol. Bull., Vol. 47, pp. 65-78, 2 figs. 
Putnam, F. W. 1864. Notes on the Habits of Some Species of 
Humble Bees. Proc. Essex Inst., Salem, Mass., Vol. 4, 
pp. 98-105. 
Rau, P. 1922. Ecological and Behavior Notes on Missouri In- 
sects. Trans. Acad. Science St. Louis. Vol. 24, pp. 1-71, 
pis. 5-8. 
1924. Notes on Captive Colonies and Homing of Bombus 
pennsylvanicus De Geer. Annals Ent. Soc. America, Vol. 
17, pp. 368-381, pi. 39. 
Root, A. I. and E. R. 1923. The A B C and X Y Z of Bee 
Culture, pp. 171-177. The A. I. Root Company, Medina, 
Ohio. 
Sladen, F. W. L. 1912. The Humble-bee, Its Life-History and 
How to Domesticate it. Macmillan & Co., London. 
