REVIEWS 563 



To the systematic geologist one of the chief points of interest in the vol- 

 ume lies in the classification of the Cretaceous formations. This is as 

 follows : 



III. The Marl series. 



5. Upper marl (in part"). 



4. Limesand (including the Yellow sand). 



3. Middle (Sevvell) marl. 



2. Red (Red Bank) sand. 



1. Lower (Navesink) marl. 

 II. Clay Marl series. 



5. Wenonah sand. 



4. Marshalltown clay-marl. 



3. Columbus sand. 



2. Woodbury clay. 



I. Merchantville clay. 

 I. The Raritan clay series. 



This subdivision, it is to be noted, is different from that which has been 

 used generally. It is adopted because, in addition to other reasons cited, 

 it is "more accurate" than the classifications heretofore published. The 

 subdivisions of the Clay-Marl series here given were made out by Mr. Knapp 

 some eight or ten years ago. It is to be noted, further, that the difference 

 between this classification and the one heretofore published^ does not 

 consist merely in the greater number of subdivisions of the several series. 

 The lines of subdivision between the major divisions are not the same as 

 in the earlier classification. Various specific errors in that classification 

 are distinctly pointed out. It may be added that, as a result of recent work 

 done by the State Survey, the subdivisions here proposed have been .shown 

 to hold paleontologicaljy as well as stratigraphically, though the results of 

 the recent paleontological studies have not been published. 



The press work of the volume is excellent, and the Survey and the state 

 are to be congratulated on the general excellence of the volume as to both 

 substance and form. 



J. H. L. 



Oil and Gas. Levels. (Vol. lA, West Virginia Geological Survey.) 

 Pp. xi + 625. I. C. White, State Geologist. 

 The earlier volume (Vol. I) of this Survey on Oil and Gas of the 

 State was exhausted some time since, and the present volume is its succes- 

 sor. In the new volume the general discussions of the previous volume 



I W. B. Clark, Annual Report, Geology of New Jersey, for 1897. 



