Reviews 



Maryland Geological Survey, Miocene. By William Bullock Clark, 

 State Geologist, 1904. 2 vols. (1) Text pp. 1-543 and Plates 

 I-IX; (2) text pp. 1-127 and Plates X-CXXXV. 



This volume is an admirable example of the results to be attained by 

 the co-operation of numerous experts organized to elaborate the various 

 aspects of a single problem in geology. Much separate and individual 

 work had already been done on the Miocene deposits of Maryland when 

 this survey began. Under the leadership of Dr. Clark, new collections 

 and new surveys were made, and with the literature and old collections at 

 hand, and by an exhaustive study of the Miocene, its stratigraphy and its 

 faunas, with refiguring of old forms and descriptions of new, a concise but 

 exhaustive monograph of the Maryland Miocene has been produced, 

 interesting to any intelligent reader. 



The introductory part is contributed by Dr. Clark. Dr. G. B. Shat- 

 tuck, who, assisted by other members of the survey, has personally con- 

 ducted the stratigraphic study in the field, writes the geological part and 

 the discussion of early literature. In this portion is found an exhaustive 

 list of species with their local distribution in eighty-eight separate stations, 

 and general distribution into the five zones into which the Miocene is 

 divided (viz., Calvert, zone 17 [lower bed], and zone 19 [upper bed] of the 

 Choptank [as a whole] and the St. Mary's formations). 



Dr. W. H. Dall writes the chapter on the relations of the Miocene of 

 Maryland to that of other regions and to the recent formations. Dr. 

 Dall supplies at the end of this part a valuable list of the species charac- 

 teristic of the North American Miocene, by which he means "the species 

 which occur only in the Miocene and occur in it from top to bottom .... 

 not at every horizon .... they have existed throughout the Miocene 

 somewhere, and disappear with the inauguration of the Pliocene" (see 

 p. cliii). 



The "Systematic Paleontology" is written by different authors, each 

 taking the group of fossils to which he has given special study. Dr. E. C. 

 Case, Dr. C. R. Eastman, E. O. Ulrich, R. S. Bassler, T. W. Vaughan, 

 Dr. R. M. Bagg, Jr., Dr. Arthur Hollick, Mr. C. S. Boyer, Dr. G. C. 

 Martin, Dr. L. C. Glenn, and Dr. W. B. Clark, each discuss one or more 

 groups of either animals or plants. 



