26 



CLASSIFICATION OF THE ANIMAL KINGDOM. 



(Gegenbaur, Studien uber Organisation und Systematik der Gtenoplioren, 

 Archiv fur Naturgeschichte, 1856 ; L. Agassiz, Contributions to the Natural 

 History of the United States of America, vol. iii., 1860.) 



Fig. 23. Ctenophora. Cesium Veneris, reduced in size. 



