128 ARCHER, ON STEPHANOSPHZRA PLUVIALIS. 
onward progress was often made in a tolerably straight line ; 
but, of course, curves and sweeps, sometimes even somewhat 
abrupt, were effected, the broader frontal margin being 
always carried in advance, the attenuated extremity always 
at the posterior. 
In this way these ameeboid bodies travelled over the field 
with quite surprising rapidity, crossing and recrossing each 
other in all directions. Under a low power, insufficient at 
first sight to show the amceboid or “ rhizopodous ” mode of 
progression, these reptant bodies might possibly have moment- 
arily called to mind so many minute green Planariz, their 
crawling movement partook so much of a regular gliding 
character. 
So rapid was the action of the pseudopodal extensions and 
that of the onward flow of the general mass, and so energetic 
was the locomotive power of these remarkable amoeboid 
bodies, that, not unfrequently, one of these primordial cells 
which had fully assumed this condition, prevented by some 
cause or other from becoming wholly extricated from the old 
Stephanospheera-globe, was actually able to drag about along 
with it (like hermit-crab and his whelk-shell) not only the old 
envelope-cell, but the perhaps still therein contained seven 
other more or less changed primordial cells; and, all the 
while, apparently not much retarded nor materially incom- 
moded by the incumbrance ! : 
It may be worth while, en passant, to note the analogy in 
the differentiation of the extremities of these amceboid bodies 
with that of Dr. Wallich’s lately described Ameba villosa* 
—the tapering, faintly granulate, posterior extremity seem- 
ing to correspond to the villous rounded organ in the actual 
Ameeba, described and figured by Dr. Wallich. This appears 
at least acurious point im common. In both the narrowed 
extremity was always posterior, the pseudopods always being 
given off from the opposite or anterior portion, and in both, 
hence, the onward progression was more direct than in most 
similar bodies, as well as more rapid ; though, so far as I can 
see, if we could imagine one of Dr. Wallich’s Amcebee pitted 
against one of my Ameebiform bodies, the former, I fancy, 
would have been beaten in the race ! 
I have, indeed, never seen any actual Amcebe, nor do I 
imagine anybody else, whose movements were so rapid 
and power of locomotion so vigorous as those of these 
amoeboid bodies of Stephanosphera. One might almost 
fancifully imagine them endowed with a will, and in an 
evident hurry to get somewhere, but unfortunately with a bad 
* ©Ann. Nat. Hist.,’ 1863, vol, xi, 2nd ser., pp. 287 e¢ seg. 
