332 Scientific Intelligence. 



observed is excitation of the L-characteristic rays of either 

 element."- Phil. Mag., 35, 59, 1918. n. s. a. 



7. A Textbook in the Principles of Science Teaching; by 

 George Ransom Twiss. Pp. xxvi, 486. New York, 1917 

 (The Maemillan Co.). — "This book is intended primarily to be 

 used in the instruction of young men and women who are pre- 

 paring themselves in colleges and normal schools for careers as 

 teachers of one or more of the natural sciences; but it is hoped 

 that it will be scarcely less useful to science teachers now in 

 service and to superintendents of school systems and principals 

 of public and private secondary schools whose duties involve 

 the direction and supervision of science instruction." The 

 nature of the subject-matter and the exhaustive treatment of the 

 field make it impossible to do justice to the volume in the space 

 at our disposal. Nothing of real value seems to have been over- 

 looked by the author. The first eleven chapters deal with gen- 

 eral pedagogical principles which are applicable Ao all phases of 

 science teaching. Chapters twelve to twenty-three are some- 

 what more specialized and they pertain primarily to biology, 

 geography, physics, chemistry, and "general science." The last 

 chapter (XXIV) relates to tests and examinations. Appendix 

 A gives a selected list of books for the high school library, while 

 appendices B and C comprise respectively bibliographies for 

 science teachers and the titles of scientific periodicals. The 

 text has been very carefully prepared and it merits the atten- 

 tion of all instructors in science who are really interested in 

 attaining as high a condition of efficiency as possible. h. s. u. 



II. Geology. 



1. The Fauna of a Medial Tertiary Formation and the 

 Associated Horizons of Northeastern Mexico; by Roy E. Dick- 

 erson and William S. W. Kew. Proc. California Acad. Sci., 

 4th ser., vol. 7, No. 5, 1917, pp. 125-156, pis. 17-26a. Climate and 

 its Influence upon the Oligocene Faunas of the Pacific Coast, 

 with Descriptions of some New Species from the Molopopho- 

 rus lincolnensis Zone; Climatic Zones of Martinez Eocene Time; 

 Ancient Panama Canals; by Roy E. Dickerson. Ibid., Nos. 6, 

 7, 8, 1917, pp. 157-205, pis. 27-31. In No. 5 of this volume of the 

 Proceedings of the California Academy of Sciences, the listed 

 fauna has 60 forms, and of these 5 are new species of echinids. 

 The horizon is that of the Bowden or Chattahoochee. Clypeaster 

 cubensis, Agassizia clevi, Lovenia dumblei, Pecten condylomatus, 

 P. oxygonum optimum, and P. gatunensis are the best guide fos- 

 sils of the medial Tertiary. 



No. 6. Even though the Oligocene of the Pacific coast is 

 between 10,000 and 15,000 feet thick, the faunas are as yet 



