c o isr T K N T s 



PAGE. 



1. Description of a New American Species of Helix. By Wes- 



ley Newcomb, JI. D 1 



2. On an Abnormal Specimen of Planorbis bicarinatus. By 



George W. Tryou, Jr 3 



.'i. Descriptions of New Fresh- Water Shells of the United 



States. By George W, Tryon, Jr 4 



4. Descriptions of New Exotic Fresh- Water Mollusea. By 



George W. Tryou, Jr 8 



5. Description of a New Species of Rissoa. By George W. Try- 



on, Jr 12 



0. Addition to "Catalogue of Helices Inhabiting the West Coast 

 of North America, North of Cape St. Lucas." By Wesley 

 N-wcomb, M.D 13 



7. Monograph of the Family Strepomatidse. (Continued.) By 



George W. Tryon, Jr 14 



8. Note on Helix rufa, DeKay. By E. Michener, M. D 53 



!). Remarks on the Origin and Distribution of the Operculated 



Land Shells which inhabit the Continent of America and 

 the West Indies, with a Catalogue of the American Spe- 

 cies. By Thomas Bland 54 



10. Note on the Internal Structure of Megaspira. By Thomas 



Bland 64 



11. Illustrations of Miocene Fossils, with Descriptions of New 



Species. By T. A. Conrad 65 



12. Note on the Genus Gadus, with Descriptions of some New 



Genera and Species of American Fossil Shells, By T. A. 

 Conrad 75 



13. Descriptions of New Species of Australian Fresh -Water 



Shells. ByT. A. Conrad 79 



14. Note on Mr, Pease's Species of Polynesian Phaneropneu- 



mona. By Geo. W. Tryon, Jr 82 



1."). On the Modern Classification of MoUusks. By O. A. L. Morch. 83 

 16. Reply to Mr. Conrad's Criticism on Mr, Gabb's '-Report on 



the Paieentology of California.' By Wm. M. Gabb 87 



EDITOFl'S TABLE. 

 Reviews : 1)3 



Aiia'ririoi. — Proceedhigs of the Academy of .Natural Sciences. 



F'lrcifjn. — Journal de Conchyliologie, ttc. 

 Scientific Intelligence 96 



NOTICE TO CONTRIBUTORS. 



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