1920] Hickernell: Digestive System of Cicada 241 



VIII. Bibliography. 



Dufour, L. (1833). Rech. anat. et physiol. des Hemipteres. 



Hargitt, C. W. (1903). The Appearance of the Periodical Cicada in Onondaga 



County. Proc. Onon. Acad. Sci. Vol. I. 

 Henderson, R. L. (1901). Unpublished paper on the Digestive System of the 



Periodical Cicada. 



Lubbock, J. (1859). On the Digestive and Nervous Systems of Coccus hesperidum. 

 Ann. and Mag. Nat. Hist. Ser. IIL Vol. III. 



Marlatt, C. L. (1898). The Periodical Cicada. U. S. Dept. Ah. Div. Ent. Bull. 



14, N. S. 

 Marlatt, C. L. (1898). U. S. Dept. Ag. Bur. Ent. Bull.71. 

 Quaintance, A. L. (1902). The Periodical Cicada and Its Occurrence in Maryland 



in 1902. Maryl. Ag. Exp. Sta. Bull. 87. 



IX. Index to Figures. 



ac — anterior crop. 



at — ascending intestine. 



cm — circular muscles. 



dt — descending intestine. 



e — esophagus. 



int — internal gland. 



k — coil in ascending intestine. 



kk — coil in descending intestine. 



mt — malpighian vessels. 



pc — posterior crop. 



r — rectum. 



X — junction of posterior crop with ascending intestine. 



y — jimction of malphigian vessel and intestine. 



