308 MR. G. S. WEST ON SOME BRITISH 
On some British Freshwater Rhizopods and Heliozoa. By 
G. S. West, B.A., F.L.S. A.R.C.S., Hutchinson Student of 
St. John’s College, Cambridge; Professor of Natural 
History at the Royal Agricultural.College, Cirencester. 
[Read 4th April, 1901.] 
(Puates 28-30, ) 
Durine the past few years I have been collecting and examining 
from every possible situation numerous small plants belonging 
to the Alge, and amongst them I have found Rhizopods and 
Heliozoa in abundance. Most of the interesting forms of these 
groups I carefully sketched, in some instances making detailed 
and extended examinations of them, and I now possess an 
accumulation of notes and drawings, many of which may be 
deserving of notice. 
Some of the observations in this paper relate to the habits 
and structure of certain of the Rhizopods and Heliozoa; others 
are descriptive of peculiar forms of the commoner and more 
abundant species, and others again are records of rarer and less- 
known species. I also give descriptions and figures of six 
animals which I believe have not previously been observed, one 
of which I have referred to a new genus (p. 325). 
A point of considerable interest is the presence of a perfora- 
tion at the apex of the shell of some forms of Difflugia acuminata, 
Ehrenb. The shell thus possesses two openings, one at each 
end, as in the case of those Rhizopods referred to the family 
Amphistomina. 
As the remarkable animals belonging to the genus Vampyrella 
possess characters by which they are sharply demarcated from 
the other Rhizopods, I have placed them in a separate order— 
the Vampyrellida. 
I have paid little attention to the species of Ameba, and it is 
very probable that I have overlooked several that are abundant 
and widely distributed. 
