PROCEEDINGS OF SOCIETIES. 125 
it often happens that only two spines seem to exist, as one is 
behind and hidden by its companion spine. Whenan oblique view 
of a cell is towards the observer, then the four spines can be at 
once seen. This plant is exceedingly minute, even the largest 
families ; and, unless when few-celled, the form of the individual 
cells, and their mode of combination, is not readily, at first sight, 
made out. This appears to be a rare little alga; Mr. Archer had, 
indeed, met with it but on two or three occasions. The present 
gathering was made in the “ Rocky Valley,” near Bray. 
Dr. John Barker showed a fine specimen of Amaba villosa 
(Wallich). Some months previously, in company with Mr. Archer, 
he had seen examples of this rhizopod; but as the character of the 
specimens did not then appear to him (Dr. Barker) as sufficiently 
well marked, and as only a comparatively few had been found in 
the gathering, he had thought it better to wait until some more 
numerous specimens should present themselves, to become quite 
satisfied as to the identity of this form. The present were taken 
from a pool in the Rocky Valley, near Bray, and in the usual rep- 
tant state he had found them to average 4,” in length, and about 
giz! in breadth. The anterior extremity is broadly rounded, the 
motion reptant, continuous, and rapid. The posterior villous en- 
largement appeared to Dr. Barker to be, as 1t were, made up of 
tubes radiating from a space clear of motile granules, and contain- 
ing one or more small vesicles. This villous patch was of a gray 
colour, and small foreign objects appeared to adhere markedly to 
it, and were carried along during the progression of the Amceba 
through the surrounding débris. The contractile vesicle appeared 
generally in the neighbourhood of the villous patch, and the nu- 
cleus was also well seen. The villous appendage sometimes ap- 
peared to be trilobed ; that is, the villous portion seemed to radiate 
from three centres. When meeting with an obstacle in front, the 
organism often put forth pseudopods from the neighbourhood of 
the villous appendage. There were specimens of Ame@ba diffiuens, 
as well as other reptant Amcebex, without pseudopods or any villous 
appendage in the same gathering. The specimens kept for upwards 
of a month, and gradually disappeared. Dr. Barker regarded these 
as all but varieties of one and the same ordinary Ameeba, influenced 
by peculiar conditions of growth, &c. 
Mr. Archer believed there could not be any doubt at all but 
that the Ameba alluded to by Dr. Barker as having been seen by 
both in company some time ago was truly none other than A. vil- 
losa (Wallich) ; just as little, indeed, as that the form now shown 
by Dr. Barker was actually the same. 
Mr. Archer, sufficiently opportunely along with Dr. Barker’s 
exhibition of A. villosa, was able to show one of those remarkable 
polymorphous conditions of the gonidia of Volvox globator first 
drawn attention to by Dr. Hicks in the ‘ Microscopical Journal.’ 
The present specimen was, indeed, languid and sluggish, as com- 
