PROCEEDINGS OF SOCIETIES. 187 
too short. But in the existent state of knowledge it would be 
eure to give this form a name. That these animals seem to 
ave a power of selection of the materials wherewith to bwi/d their 
habitations is evident. D. pyriformis seems to use very small, 
tolerably regular-sized, particles; the horned’ form huge crags and 
boulders (microscopically speaking) in comparison, as well as 
large Pinnularia frustules, &c.,and these laid on in any and ever 
way, and projecting irregularly in every direction. Whilst the 
surface of the first seems somewhat evenly paved, the latter carries 
about a complete little rockery, and this, added to the different 
form of each, gave them a character that stamped them at once. 
Again, as bearing on external distinctions, Mr. Archer’s atten- 
tion was first attracted to the solitary Gromia on the slide, not by 
its pseudopods, for they were not then visible, but, even under a 
low power, by its contour, for its opaque test had much the same 
colour ‘as the Difflugie. Here was an egg-shaped form, its surface 
less rough than that of the Difflugiz around; this was enough to 
attract observation. Upon the slide being laid aside for a little, 
however, and this egg-shaped form again examined, there were the 
beautiful pseudopods of this curious creature expanded to the 
full, to three, four, or even five times the length of the test, rami- 
fying in every direction, and inosculated here and there, and 
occasionally expanded. The majority of the pseudopods projected 
in front, but, as in Carpenter’s well-known figure, not a few 
radiating laterally and posteriorly, and a beautiful “ circulation” 
going on like that of the protoplasm of the cells of the hairs of the 
stamens of Tradescantia. Now, here external form and external 
character were enough to indicate that this was, at all events, not 
the same thing as the Difflugie around; actually how very 
different has been seen. It could not be contended that Kuglypha 
is not a different thing from Difflugia, per se, nor can any genetic 
affinity be founded on possibilities. Another curious Rhizopod in 
the present gathering was the Plagiophrys. Mr. Archer’s only 
acquaintance with the genus was that afforded in Dr. Carpenter’s 
work, for he had not Claparéde’s work. But at all events here 
was a type quite distinct, be it referred correctly or not to that 
nus. It did not appear to agree quite with the figure given by 
arpenter; the body was elliptic, minute, and the pseudopods 
emanating from one spot in a kind of tuft, not distributed, and so 
it approached more to a Lagynis, as it were, without a test. Of 
the Actinophrys it is, of course, unnecessary to speak. 
Now, if Dr. Wallich be right in assuming that, the animals 
being alike in Difflugie, the different forms are but the result of, 
and in obedience to, local conditions—how could these several 
distinct. and varied forms, not to speak of different types of 
Rhizopods, be the products of identically the same circumstances 
and exactly the same local conditions—that is, how could one and 
the same cause produce several distinct results? It is argued 
that the tests only are different—that the animals are alike—but 
not more alike than the cell-contents, the analogous portion, in 
