CONTENTS 



PAGE 



Heath, Harold. The anatomy of two Brazilian land shells, 



Anostoma depressum and Tomigerus clausus (Plate 



XXXI) '. 688 



Hebard, Morgan. A revision of the ' species of the geniis 



Nemobius (Orthoptera: Gryllidse) found in North 



America north of the Isthmus of Panama 394 



Palmer, T. Chalkley. The collecting and preparation of 



diatoms 580 



PiLSBRY, Henry A., Sc.D. Notes on some Lower Californian 



Helices (Plates XV, XVI) 380 



Reiin, James A. G. Descriptions and records of South 



American Orthoptera, with the description of a new 



subspecies from Clarion Island 82 



A contribution to the knowledge of the Orthoptera of 



Argentina 273 



Stone, Witmer. On a collection of birds obtained by the 



Francis E. Bond Expedition in the Orinoco Delta and 



Paria Peninsula, Venezuela 189 



Thompson, J. C, M.D. Oxyrhopus trigeminus Dumeril and 



Bibron the type of Erythroxyrhopus gen. nov. 78 



Notes on serpents in the family Colubridse 213 



Contributions to the synonymy of serpents of the family 



Lapida? 508 



Vanatta, E. G. Descriptions of new species of marine shells 



(Plate II) 22 



Weidman, Fred D. A study of metazoan parasites found in 



the Philadelphia Zoological Garden (Plate IV) 126 



Wherry, Edgar T., Ph.D. North border relations of the 



Triassic in Pennsylvania (Plate III) 114 



