ANIMAL EVOLUTION 



54i 



earlier papers form the connecting link between Dr. 

 Clark's ideas and those of other zoologists.) 



The steps in the evolution of animals. Journ. Wash- 

 ington Acad. Sci., vol. 11, No. 9, May 4, 19x1, 

 pp. 2.07-Z08. 



A new classification of animals. Bulletin de l'lnstitut 

 oceanographique, Monaco, No. 400, September 

 zo, 19Z1, pp. 1-14. 



(The evolution of the animal body. Journ. Washing- 

 ton Acad. Sci., vol. iz, No. z, January 19, 192.2., 

 pp. z 5 -z8. 

 Vnimal evolution. Proc. Nat. Acad. Sci., vol. 8, No. 

 7, July, 19*1-, pp- 2.19-2.2.5. 



The origin of the vertebrates. Journ. Washington 

 Acad. Sci., vol. 13, No. 7, April 4, 19^3, pp. 12.9- 

 138. 



A comparative study of the most ancient and the 



recent marine faunas. Journ. Washington Acad. 



Sci., vol. 14, No. 2.1, December 19, 192.4, pp. 



487-491. 

 Observations on animal coloration. Scientific 



Monthly, vol. zo, No. 4, April, 19Z5, pp. 341-344. 

 Animals of Land and Sea. D. Van Nostrand Co., 



New York, 19Z5. Chapman and Hall, Ltd., 



London, 1916. Second enlarged edition, D. Van 



Nostrand Co., New York, 19Z7. 

 Animal voices. Scientific Monthly, vol. zz, January, 



19Z6, pp. 40-48. 

 The biological relationships of the land, the sea, and 



man. Science, new series, vol. 65, No. 1680, 



March 11, 19Z7, pp. Z41-Z45. 

 Geography and zoology. Annals of the Assoc, of 



American Geographers, vol. 17, No. 3, September, 



19Z7, pp. 101-145. 



