278 Mr. Henry B. Brady on 
associated in deep water with Orbulina, are not unfrequent in 
our brackish gatherings. 
Rotalia Beccarit exhibits modifications of somewhat different 
occasional communieation with the sea. 
The importance of these facts consists chiefly in the light 
they seem to cast upon the relation between some of the ma- 
rine and freshwater groups of Protozoa. The physical and 
(of course excluding the Polycystina), is a question upon which 
we are not yet prepared to enter, 
