255 
In the first place, I noticed that the short, slender, tapering 
and pointed rays were not always vertical, hut lying in 
various directions. I saw too, shortly, in some specimens, 
that they were readily shed, and then that they were capitate 
at the louver end. A little more pressure, and the little, 
short, slender, peripheral bodies became evident and readily 
removable. All this could not happen were this body a 
rotatorian egg. In fact, without any hesitation, I felt satis- 
fied I had before me a new form referable to Carter’s genus 
Acanthocystis, which diagnosis was fully confirmed on finding 
examples fully displaying pseudopodia. I could never see 
any trace of either * nucleus’ or vacuole. It, of course, struck 
me that this form might have been previously encountered, 
and that there was a possibility of the spines being taken for 
pseudopodia, which they, no doubt, at first resemble, and on 
reference to Perty ’s work a form presents itself, as has been men- 
tioned (1. c.), with which this may possibly be really identical, 
though I fear the data afforded are by no means sufficient to 
decide this point. But if my form is, in fact, Perty’s 
Actinophrys brevicirrhis, nothing can be more certain than 
that he has misapprehended the characters presented, and 
that for a time, like myself, having seen only specimens with 
the pseudopodia not extended, he has mistaken the spines for 
pseudopodia. A further ground, too, is given to this assump- 
tion by his figure showing some of the rays (not to call them 
either spines or pseudopodia) as variously directed, not truly 
vertical. My form has, moreover, greenish contents, though 
I have not seen any of so great depth of colour as in A. tur- 
facea. But he gives no good indication of the peripheral 
spicules in his drawing. Be this as it may, I feel satisfied 
that my animal finds its true place in the genus Acantho- 
cystis, and as commemorative of Perty’s labours, I have plea- 
sure in naming this little form Acanthocystis Pertyana. 
Rajdiidiophrys viridis, gen. et sp. nov. (PI. XVI, fig. S.j 
On the occasion of my first chronicling in the “ Minutes of 
the Dublin Microscopical Club ” the discovery of this fine 
rhizopod, one of the most noble, probably, to be found in fresh 
water, I designated it as of a type roughly definable as an 
Actinophrys p>las spicula. But it is actually of a structure 
more differentiated in some respects than that expression 
would convey, for if we would imagine an Actinophrys 
densely studded at its periphery by some unknown agency 
with a multitude of such acicular spicula as occur in this 
species, we should have something like it, it is true, but 
