FURTHER NOTES ON THE PALEONTOLOGY OF 

 ARRESTED EVOLUTION 



DR RUDOLF RUEDEMAOT 

 State Museum, Albany, N. Y. 



The writer has in a former paper^ endeavored to fol- 

 low np the causes of persistence as seen from the side 

 of the paleontologist. Using as a basis the genera which 

 appear in Zittel-Eastman's Textbook of Paleontology 

 (1913) and defining as persistent all genera which pass 

 through more than two periods, the following data rela- 

 tive to number of persistent genera (^4), total number 

 of genera cited (B), and percentage of persistent genera 

 (C) were obtained: 



iR. Buedemann, "The Paleontology of Arrested Evolution." Presi- 

 dential Address. Albany, 1916. New York State Museum Bull. 196, 1918, 

 pp. 107-138. 



256 



