CONTENTS. 



Page 

 Art. I. On the Embryology of Nemertes, with an Appendix on the 

 Embryonic Development of Polynoe ; and Kemarks upon 

 the Embryology of Marine Worms in general. By E. De- 



sor, Boston 1 



Art. II. Descriptions and Figures of the Araneides of the United 

 States. By Nicholas Marcellus Hentz, Tuscaloosa, 



Alabama 18 



Art. III. Chemical Examination of some American Minerals. By J. 



D. Whitney, Boston 36 



Art. IV. Examination of three new Mineralogical Species proposed by 



Prof. C. U. Shepard. By J. D. Whitney ... 42 

 Art. V. Observations on some of the Habits of Salrno Fontinalis. By 



Samuel L. Bigelow, M. D., Worcester . . , .49 

 Art. VI. Description of a new Genus of Eishes, Malacosteus. By 



W. O. Ayres, Boston 53 



Art. VII. On the Pselaphidse of the United States. By John L. Le 



Conte, M. D., New York 64 



Art. VIII. Dissection of Crocodilus lucius. By Samuel Kneeland, Jr., 



M. D., Boston 110 



Art. IX. Chemical Examination of Algerite, a new Mineral Species 5 

 by T. S. Hunt, of the Geological Commission of Canada ; 

 including a Description of the Mineral, by F. Alger, 



Boston 118 



Art. X. Examination of a Mineral from Cherokee County, Georgia. 



By Francis Alger, Boston 123 



Art. XI. On the Cancellated Structure of some of the Bones of the 

 Human Body. By Jeffries Wyman, M. D., Cam- 

 bridge 125 



Art. XII. Plants Lindheimerian^e, Part II. An Account of a 

 Collection of Plants made by F. Lindheimer in the western 

 part of Texas, in the years 1845-6, and 1847-8, with Criti- 

 cal Bemarks, Descriptions of New Species, &c. By Asa 

 Gray, M. D., Cambridge . . . . .141 



