THE 



AMERICAN JOURNAL OF SCIENCE 



[FOURTH SERIES.] 



Art. TIL — Revision of the Protostegidce ; by G. R. 

 Wieland. '(With Plates II-IY.) 



[Contributions from the Paleontological Laboratory of Yale University.] 



There is no family among all American fossil turtles which, 

 following the discovery of its initial type, has so steadily 

 yielded new forms and additions to our knowledge of the 

 structure and history of marine turtles as the Protostegidse. 

 True enough, no further members of the family were noted 

 and few specimens were collected for twenty years after Cope's 

 original discovery of Protostega gigas / but then came the 

 addition of the related genus Archelon from the Pierre Cre- 

 taceous in 1895, since which time scarcely a year has passed 

 without yielding new data to the structure, extent and signifi- 

 cance of the Protostegidse. 



Indeed, even before the discovery of Archelon the attention 

 of the brilliant and incisive Baur had been turned to Protos- 

 tega ; and since then Hay, Case, Williston and Wieland have 

 all contributed in turn to the literature of the Protostegidse, — 

 while in Europe Dollo has published papers of the greatest 

 supplemental interest dealing with the origin of marine turtles. 



Furthermore the collection of the splendid cotypes of Pro- 

 tostega gigas showing the complete limb structure, now in the 

 Carnegie Museum of Pittsburg, and more recently the mount- 

 ing for exhibition of the huge type of Archelon ischyros in 

 the Yale Museum, have contributed much toward the increas- 

 ingly accurate picture of the Protostegidse. With the descrip- 

 tion of new species, meanwhile, and the appearance of the 

 great volume of Hay — easily the foremost contribution to the 

 literature of the Testudinata yet made — it is already evident 

 that the Protostegidse include a series of forms of the greatest 

 structural interest, and that further additions to the family are 



Am. Jour. Sci. — Fourth Series, Vol. XXVII, No. 158. — February, 1909. 



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