vi SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 52 



Page 



Observations on Living White Whales (Delphinapterus Leiicas) ; with a 

 Note on the DentitioVi of Delphinapterus and Stenodelphis. Fred- 

 erick W. True. Plate xxiii. (Published April 28, 1909.) 325 



Some Recent Contributions to Our Knowledge of the Sun. Hamilton 

 Lecture. George E. Hale. Pl.ates xxiv-xxxvi. (Published May 

 8, 1909.) 331 



Some Nezu South American Land Shells. William H. Dall. Plate 

 XXXVII. (Published May 11, 1909.) 361 



The American Ferns of the Group of Dryoptcris Opposite Contained in 

 the U. S. National Museum. Carl Christexsen. (Published July 

 12, 1909.) 365 



Notes 397 



Prehistoric Ruins of the Gila Valley. J. Walter FewkEs. Plates 



xxxviii-XLii. (Published August 4, 1909.) 403 



Description of -a Neiv Frog from the Philippine Islands. Leoxhard Stej- 



NEGER. (Published August 4, 1909.) 437 



A Neiv Genus of Fossil Cetaceans from Santa Crus Territory, Patar 

 gonia; and Description of a Mandible and Vcrtebrce of Prosqualodon. 

 Frederick W. True. Plates xliii-xlv. (Published August 7, 1909.) 44i 



Notes on Certain Features of the Life History of the Alaskan Frcshzvater 

 Sculpin. Barton A. Bean and Alfred C. Weed. (Published August 

 19, 1909.) 457 



The Geologic Work of Mangroves in Southern Florida. T. Wayl.\nd 

 Vaughan. Plates xlvi-lii. (Published September 15, 1909.) 461 



Crystallo graphic Notes on Calcite. J. E. Pogue. Plates liii, liv. (Pub- 

 lished September 24, 1909.) 465 



A Nezv Rodent of the Genus Georychns. Edmund Heller. Pl.\te lv. 



(Published September 24, 1909.) 469 



Two Nezv Rodents from British East Africa. Edmund HellER. Plate 

 LVL (Published November 13, 1909.) 471 



A Heretofore Undescribed Stony Meteorite from Thomson, lilcDufHe 

 County, Georgia. George P. Merrill. Plates lvii, lviii. (Pub- 

 lished December 2, 1909.) 473 



On a Remarkable Cube of Pyrite, Carrying Crystallized Gold and Galena 

 of Unusual Plabit. J. E. Pogue. Plate lix. (Published December 

 22, 1909.) 477 



A Nezv Carnivore from British East Africa. Gerrit S. Miller, Jr. 

 Plates lx-lxii. (Published December 18, 1909.) 4S5 



Descriptions of Fossil Plants from the Mesozoic and Cenozoic of North 

 America. L F. H. KnowlTon. Pl.vtes lxiii, lxiv. (Published Jan- 

 uary II, 1910.) 489 



Tzvo Nezv Genera of Murine Rodents. Gerrit S. ^IillEr, Jr. (Pub- 

 lished January 12, 1910.) 497 



A Shelter for Observers on Mount Whitney. C. G. Abbot. Plates lxv, 



Lxvi. (Published January 12, 1910.) 499 



