AM@BA VILLOSA. 51 
In size rivalling the larger forms of Ameba proteus, 
sometimes attaining, according to Wallich, a diameter 
of one-fiftieth of an inch. The body, at its posterior 
extremity, has a villous discoid or lobed protuberance, 
which, whilst capable of modification within certain 
limits, is persistent. Its precise function, however, is 
not evident. In all other respects the animal closely 
resembles, even in the young state, the larger forms of 
A. proteus. The nucleus and contractile vacuole are 
normally in the posterior region, the former ovoid 
and punctated like that of A. proteus, the punctula- 
tions being disposed longitudinally. Locomotion is 
effected by lobular expansions of the ectoplasm, 
anterior or lateral, or by digitate pseudopodia, which 
may emerge on one side (with the result of altering 
the line of “progression) or from all sides at once, when 
the appearance shown in Pl. II, fig. 2, is presented. 
The villous appendage does not appear to be affected 
by any pseudopodal movements. The colour of the 
endoplasm is usually a creamy-white, greyish in the 
denser parts, granular, and containing green and other 
corpuscles resembling those observed in A. proteus, 
and not infrequently also desmids and other alge. 
Dimensions variable; elongated examples often 
attaining a length of 250 uw or more. 
Ponds at Hampstead, 1863 (Dr. Wallich); in similar 
situations in Cheshire; in the Rossendale district of 
Lancashire (J. H. Lord); near Bingley, West York- 
shire (G. S. West). 
Ameba villosa was first detected by Dr. Wallich in 
India, and he published a description of it in the 
‘ Annals’ (J. c.)in the year 1863. Returning to England 
he found it at Hampstead. We suspect, however, 
from Mr. H. J. Slack’s description of some examples 
from the last-named locality, in the ‘Intellectual 
Observer,’ Vol. III, p. 430, that the much larger and 
coarser-looking organism, Pelomywa villosa Leidy, 
was mistaken for it. The two species may have been 
