$1.00 per Year. ($1.12 to Foreign Countries ) lOcts. a copy. 



THE 



NAUTILUS 



A MONTHLY 



DEVOTED TO THE INTERESTS 





 OF CONCHOLOGISTS. 



EDITOR : 

 H. A. PILSBRV, Conservator Conchological Section, Academy of Natural Sciences, Philadelphia 



ASSOCIATE EDITOR : 

 C. W. JOHNSON, Curator of the Wagner Free Institute of Science, 



Vol. X. SEPTEMBER, 1896. N o . 5 



CONTENTS : 



PAGE. 



NOTES ON SOME WEST AMERICAN CHITONS. By H. A. Pilsbry. . 49 



ON THE AMERICAN SPECIES OF CYRENOIDEA. By W. H. Dall. . . 51 



EDITORIAL CORRESPONDENCE. ...... 53 



ISAAC LEA DEPARTMENT. ...... gg 



MARINE SHELLS ON THE SOUTHERN CAI IFHRNIA COAST. By Mrs. E. D. G. 



Campbell. ......... gg 



NOTES ON THE PARVUS GROUP OF UNIONID.-E AND ITS ALLIES. 



By C. T. Simpson. 57 



NOTES AND NEWS gg 



NEW PUBLICATIONS RECEIVED 



Published by 



H. A. PILSBRY, Editor, Academy of Nat. Sciences, Philadelphia. 



C. W. JOHNSON, Manager, Wagner Free Institute of Science, Philad'a. 



Entered at Philadelphia Post-Office as second-class matter. 



