CONTENTS. 



I'AGE. 



Leidy, Joseph, M. D. Beroe on the New Jersey Coast 341 



PiLSBRY, H. A, Trochidge, new and old. 343 



Wachsmuth. Charles & Frank Springer. The perisomic plates of the Crinoids. 



(Plates IX, X) 345 



Heilprin, Angelo. The Eocene Mollusca of the State of -Texas. (Plate XI). . 393 

 Ryder, John A. The functions and histology of the Yolk-sac of the Young Toad- 

 fish 407 



Leidy, Joseph, M. D. Remarks on Velella - . 408 



Leidy, Joseph, M. D. Notices of Entozoa 410 



Bancroft, Edward. Co-ossification of Axis Vertebra with Third Cervical. . . 419 

 Stone, Witmer. Pennsylvania and New Jersey Spiders of the Family Lycosidae. 



(Plate XV.) 420 



Rand, Theodore D. Geology of the South (Chester) Valley Hill. . . . 435 



Rex, Geo. A., M. D. Trichia proximella Karst 436 



WiNGATE, Harold. Note on Stemonitis maxima Sz. 438 



Dixon, Samuel G., M. D. The development of Bacillus tuberculosis. . . . 438 



PiLSBRY, Henry A. Description of a New Japanese Scalpellum. .... 441 



WooI-Man, Lewis. Geology of Artesian Wells, Atlanlic City, N. J. ... 444 



Heilprin, Angelo. The geology and paleontology of the Cretaceous Deposits of 



Mexico. (Plates XII, XIII, XIV) 445 



Report of Recording Secretary. .......... 470 



Report of Corresponding Secretary. .......... 471 



Report of Librarian. ............ 472 



Report of Curators. (Plates XV, XVI, XVII) 474 



Report on the Operations of the Expedition to Yucatan and Mexico 478 



Report of the Biological and Microscopical Section. ....... 480 



Reiwrt of the Conchological Section. ......... 481 



Report of the Entomological Section. ......... 483 



Report of the Botanical Section. . 484 



Report of the Mineralngical and Geological Section. ....... 486 



Report of the Professor of Invertebrate Paleontology. ...... 487 



Report of the Professor of Ethnology and Archaeology. ...... 487 



Report of the Professor of Invertebrate Zoology. ....... 488 



Report of the Curator of the William S. Vaux Collections. ..... 489 



Officers, Couneillors and Finance Committee for 1891. ...... 490 



Elections. 490 



Additions to Museum. 492 



Index to Genera 498 



