CONTENTS 
New Species of North American Bees of the Genus Andrena 
contained in the Collection of the Academy of Nat- 
ural Sciences of Philadelphia. By Henry L. Viereck 365 
(Issued November 14, 1917.) 
Notes on Mexican Detmaptera. • By Morgan Hehard 409 
(Issued December 10, 1917.) 
Studies of North American Plecoptera (Pteronarcinae 
and Perlodini). By Lucy Wright Smith . 433 
(Issued December 2S, 1917.) 
