iv CONTENTS. 



Ko. 11. — On some Young Stages In the Development of Ilippa, Porcellana, 



and Pinnixa. By W. Faxon. (6 Plates) 253 



Hippa 253 



Porcellana 256 



: Bibliography 261 



Pinnixa 263 



No. 12. — Reports on the Dredging Operations of the United States Coast 

 Survey Steamer " Blake." IV. Preliminary Keport on the Worms. By 

 Professor Ernst Ehlers of Gcittingen ....... 269 



No. 13. — On the Classification of Rocks. By M. E. Wadsworth . . 275 



No. 14. — Letter No. 3 to C. P. Patterson, Superintendent United States Coast 

 Survey on the Dredging Operations of the United States Steamer " Blake." 

 By A. Agassiz. (2 Maps) 289 



No. 15. — On the Development of Palaemonetes Vulgaris. By Walter 

 Faxon. (4 Plates) 303 



No. 16. — On the Jaw and Lingual Dentition of certain Terrestrial MoUusks. 

 By W. G. BiNNBY. (2 Plates) 331 



