SYSTEMATIC SURVEY. 



107 



large group, among which are such familiar forms as the common 

 Engh'iia of ponds ; the Monads ; Volvox, a colonial form ; Codosiga, a 

 colony in which the individual cells are furnished with a collar. 



Modified flagellate forms are included in the groups (9) Dino- 

 flagellata and (10) Rhynchoflagellata, in both of which there are two 

 flagella, differently placed in the two cases. In the first are included 

 Peridinium and Ceratium ; in the latter, the large phosphorescent 

 Noctihica. 



FIG. 49. A pelagic Foraminifer ILntigerina (Globigerina) 

 Murray i. After Brady. 



Note central shell, projecting calcareous spines with a protoplasmic 

 axis ; also fine curved pseudopoclia and vacuolated protoplasm. 



As (11) Ciliata arc included a very large number of forms, more or 

 less closely resembling Paraiiittciuin, and very abundant in infusions ; 

 some, such as Opalina, in the intestine of the frog, are parasitic. The 

 cilia often vary in size and distribution, and constitute a basis of 

 classification. 



As specially modified Ciliata are included (12) Acinetaria, highly 

 specialised forms, ciliated when young, but usually furnished when adult 



