68 
at an almost constant temperature of 8° R. by day, and is 
never dried up. The fauna of these moor-pools, with regard 
to the character of the creatures inhabiting them, the number 
of the species they contain, and the rarity of these species, 
varies very much from time to time ; this is probably due 
partly to differences in the quantity of water in the stream, 
and partly to some mixture of it with rain water or water 
from some other source. Desmidiacese and Diatomaceae were 
also observed ; the number of forms was small, some of the 
species being rare, but the variety of specimens not very 
remarkable. At different periods of the year the predomi- 
nant species inhabiting these pools are replaced by others. 
With regard to the Radiolaria, nothing has yet been deter- 
mined on this point, since from the time of their discovery 
attention has been almost exclusively devoted to the new and 
particular forms brought under notice during three months of 
summer. 
The first sign of Radiolaria was presented in a small glass 
vessel filled with moor water, one side of which, turned 
towards the light, presented a bright-green lining, formed by 
numerous Desmidiaceae. Whilst searching amongst the green 
globules, discs, fronds, &c., for fitting specimens, I met with 
a small green round body, which appeared to be surrounded 
by a layer of jelly-like material. After this had been re- 
moved with a pipette, and placed upon an object-bearer, I 
found that it was a globular body indicating Pandiorna vnorum 
or some allied form. On repeated examination I discovered 
that there was a great difference between the impression that 
had been made bv the object first presented and that of the 
round body in the field of the microscope; the conviction 
was consequently forced upon me either that I had not 
removed the proper body with the pipette, or that its cha- 
racter had been altered during the transmission. Whilst 
endeavouring to clear up this obscurity by employing a 
stronger magnifying power, I was called away. On my return 
I was not a little surprised at the change that had occurred. 
A covering of delicate sarcode had developed itself as a broad 
border around the globular body, from which numerous 
extremely fine, long, and pointed processes now passed out- 
wards in a radiating direction. By peculiar to-and-fro 
movements which accompanied the elongation and retraction 
of these processes, slow and irregular locomotion, apparently 
working in one fixed direction, was produced. This, then, 
was a discovery of a previously unrecognised animalcule, 
which, indeed, at first sight seemed to bear some affinity to 
the Rhizopoda, and, in particular, to the Actinophrys, but 
