84 MANUAL OF ZOOLOGY. 



probably be looked upon as a flagellate Infusorian, but it is 

 placed by M. de Quatrefages amongst the Rhizopoda. 



AFFINITIES OF THE INFUSORIA. Though generally placed 

 amongst the Protozoa, of which they form the highest division, 

 the position of the Infusoria cannot be looked upon as defi- 

 nitely settled. There is a growing opinion amongst competent 

 authorities that the Infusoria should be entirely removed from 

 the Protozoa, and that they should be placed amongst the An- 

 nuloida, having their nearest allies in the Turbellarian Worms. 

 If this change be carried out, the Infusoria &&& Rotifera, which 

 older naturalists grouped together, and which modern ob- 

 servers have placed widely apart, will be again brought nearly 

 together. If the sponges also should be removed from the 

 Protozoa, as is maintained by some modern observers, then 

 the entire sub-kingdom of the Protozoa would contain only the 

 Gregarinida, Amcebea, Foraminifera, and Radiolaria. At pre- 

 sent, however, there certainly do not appear to be sufficiently 

 decisive grounds for such a step ; and the affinities of the 

 Spongida are certainly more intimate with the typical Rhizopods 

 than with the Ccel&itirata. 



