MICROSCOPIC LIFE OF THE " LEAF-CARPET." 237
The most constantly occurring species, in the order of the
total number of records in each case, were as follows:—Trinema
enchelys, Difflugia constricta, Euglypha ciliata, Corythion dubium,
Trinema lineare, Difflugia globula, Euglypha laevis (?), Crypto-
difflugia oviformis, Euglypha denticulata. Sphenoderia dentata,
Trinema complanatum, Assulina muscorum and Nebela collaris.
These therefore may be regarded as the typical forms of testaceous
Rhizopods of the leaf-carpets examined. The following is the
complete list of species under their respective genera:—
Arcella. The usual form of this was what appeared to be
A. discoides, but it was only seen seven times. A. vulgaris was
only seen on two occasions.
Pseudochlamys. The species P. patella was seen definitely
only on one occasion and doubtfully on another.
Microcorycia. M. radiata was certainly seen only on one
occasion and M. flava (?) also once.
Difflugia. By far the commonest species of this genus were
D. constricta and D. globula, but D. arcula was seen many times.
Other species recorded only once or twice were D. penardi, D.
lucida (?) and D. manicata (?).
Cryptodifflugia. A common and very characteristic testaceous
Rhizopod in the leaf-carpet has been a small (15—20µ, rarely up
to 25µ) chitinous ovoid form undoubtedly nearly related to and
probably identical with Cryptodifflugia oviformis, Penard (figs.
1—5). The chief difference appears to be that whereas the latter
is said to be more or less compressed, the leaf-carpet specimens
were always circular in section and the small mouth was also
circular. They were also nearly always of a dark reddish-brown
colour, a point, however, of doubtful significance seeing that in
two collections almost colourless specimens were found and that
in one case, where two individuals were joined mouth to mouth,
one was dark and the other nearly colourless. I suspect that
Geococcus vulgaris, France (2) is the same as the leaf-carpet form.
Should this prove to be so and a distinction established between
them and C. oviformis, then their proper designation would be C.
vulgaris, since the genus Geococcus seems evidently to come
within the earlier established Cryptodifflugia
In addition to the characters mentioned above, the following
details may also be given:—Test very variable in shape ranging