516 Scientific Intelligence. 



8. The dossil Turtles of North America ; by Oliver Perry 

 Hay. Pp. 568, with 704 illustrations in text and 113 plates. 

 Carnegie Institution of Washington, Publication No. 75, Wash- 

 ington, 1908. — All naturalists welcome this sumptuous volume on 

 a subject that has too long remained in confusion by reason of a 

 large number of imperfectly known forms and the even more 

 serious lack of field work. Here, finally, the isolated facts are 

 assembled and redescribed, and with many new discoveries, 

 illustrated with a clearness and fulness that disarms all criticism. 

 If one washed to see a few more references to European turtles, 

 with the introduction of at least occasional comparative figures, 

 the great size already reached by the volume would preclude 

 fairness in such a wish. We do think, however, that omission 

 from the legends of the source of adopted figures, and some- 

 times of plates, is not commendable. Fulness of legends affords 

 one of the most effective aids in text condensation. 



In completing his summary of the fossil turtles of North 

 America, Dr. Hay finds 268 valid species, 76 of which are new. 

 The Bridger Eocene has been particularly prolific in new forms, 

 also the Laramie and Judith River Cretaceous; while the genus 

 Glyptops, oldest of American forms, is found to include three 

 new species and to extend into the uppermost Cretaceous. Our 

 turtles culminated in size in the Fort Pierre, with also the great- 

 est number of more or less distinctly salt-water forms ; fresh- 

 water forms were most numerous in the Bridger Eocene, and 

 land forms at their largest in the late Tertiary. The presence 

 of pleurodiran genera in the earlier faunae is very interesting. 



It is not clear why our pioneer collectors so persistently neg- 

 lected the Testudinata, leaving nearly to accident until very 

 recently the accumulation of adequate material for establishing 

 the ancient history of this group. Highly modified, the most 

 widely distributed of all the reptilian orders in both latitude and 

 time, yet bound to be of stratigraphic value, and barely past their 

 culmination in number and size, the turtles must, according to 

 any fair hypothesis, finally yield a vast fund of information con- 

 cerning evolutionary limits ; they must, too, shed much light 

 problems of distribution. Their study, fortunately, is now set ai 

 far ahead as that of any other of the more extensive groups >f 

 fossil vertebrates yielded by this continent, if not indeed f urth. 

 Dr. Hay's volume is, then, to say the least, epoch-making ; for i 

 comparable, work on fossil turtles has appeared in Europe. An . 

 it is furthermore noteworthy from this symposium of Americi v 

 turtles, and especially from the large number of new forms added 

 by Dr. Hay and others during the past ten years, augmenting 

 previously known species by fully sixty per cent, that North 

 America will eventually yield an enormous fossil turtle fauna. 

 Particularly in the case of the more primitive forms and the 

 Protostegidas may we anticipate early results from exploration. 

 The Carnegie Institution has thus opened to other workers a 

 great field in which progress is now rendered rapid and accurate. 



g. r. w. 



