IV. 



Contents. 



XXI. On the Existence of siliceous (?) Spiculcein the exterior Rays 

 of Actinia ; and Memoranda concerning the siliceous 

 Animalcules of Boston. 5i/ Prof. J. W. Bailey, - 252 



XXII. Enumeration of the Fishes of Brookhaven, Long Island, with 

 Remarks upon the Species observed- By William O. 

 Ayres, --- 255 



XXIII. Enumeration of the Fishes of Brookhaven, S^c. By William 



O. Ayres, (continued from p. 264), ... - 265 



XXIV. Descriptions of four Species of Fishes from Brookhaven, 



L. I., all of which are believed to be tiew. By Williaji; 



0. Ayres, 293 



XXV, Descriptions of the Fishes of the Ohio River and its Tribu- 

 taries. By Jared p. Kirtland, M. D., (continued from 



p. 240), 303 



XXVI. Catalogue of the marine, fluviatile, and terrestrial Shells of 

 the State of Maine and adjacent Ocean. By J. W. 

 MiGHELS, M. D., 308 



XXVII. Descriptions of six Species of Shells, regarded as new. By 



J. W. MiGHELs, M. D., 345 



XXVIII. Monograph of the Species of Pupa found in the United 

 States, with Figures. By Augustus A. Gould, M. D. 

 (continued from iii. 404), ...... 350 



XXIX. Descriptions of two undescribed Species of North American 



Helices. By Amos Binney, .--.-. 360 

 XXX. Observations on the external Characters and Habits of the Tro- 

 glodytes JVisrer, Geof. By Thomas S. Savage, M. D. ; 

 and on its Organization. By Jeffries Wyman, M. D., - 362 



XXXI. Descriptions and Figures of the Araneides of the United 



States. By N. M. Hentz, (continued from p. 231), - 376 



XXXII. Description of an African Beetle, allied to Scarabaus Poly- 

 phemus, tvith Remarks upon sotne other Insects of the same 

 Group. By T. W. Harris, M. D., .... 397 



XXXIII. On the Importance of Habit as a Guide to Accuracy in sys- 



tematical Arrangement, illustrated in the Instance of the 

 Sylvia petechia of Wilsoti. and all subsequent Writers. 

 By Thomas McCulloch, Jr., ------ 406 



XXXIV. On the Anatomy of Tebennophorus Carolinensis. By Jef- 



fries Wyman, M. D., 410 



XXXV. On the anatomical Structure of Glandina truncata of Say. 



By Jeffries Wyman, M. D., ------ 416 



XXXVI. Beaumontite and Lincolnite identical with Heulandite. By 



Francis Alger, 422 



XXXVII. Probable Influence of Icebergs upon Drift. By J. L.Hayes, 426 



JLXJLV III. Descriptions of Land Shells from the Province of Tavoy, in 



British Burmah. By Augustus A. Gould, M. D., - 452 



XXXIX. Descriptions and Habits of some of the Birds of Yucatan. By 



Samuel Cabot, Jr. M. D., 460 



XL. Enumeration of the recent freshwater Mollusca ivhich are com- 

 mon to North America ayid Europe ; with Observations on 

 Species and their Distribution. By S. S. Haldeman, - 468 



XLI. Descriptions and Notices of some of the Land Shells of Cuba. 



By Augustus A. Gould, M. D., ----- 485 

 XLII. Miner alogical Notices. By J. E. Teschemacher, - - 498 

 XLIIl. Analysis of Pink Scapolite, and of Cerium Ochre, from Bol- 

 ton^ Mass. By Charles T. Jackson, - - - - 504 



