MR. G. S. WEST ON SOME CRITICAL GREEN ALG JE. 283 
During May some of the cells formed gametes, which differed from the 
zoogonidia in their smaller size and greatly reduced processes (fig. 16). In 
fact, the latter were only discernible as very minute conical warts. These 
gametes, which, so far as I could ascertain, arose 16 in a mother-cell, con- 
jugated in pairs and formed globular zygospores with smooth walls. 
As is usual in so many cultures of Alge, some of the individuals were 
distorted and monstrous. The commonest distortion from the original type 
was an inflated, swollen individual, in which the body of the cell was 
spherical, the processes appearing correspondingly small (fig. 18). These 
individuals only appeared in a three-months culture. The most interesting 
monstrous form was an incomplete separation of two individuals, owing to 
imperfect division of the contents of the mother-cell during the formation of 
zoogonidia (fig. 19). 
After much consideration I have referred the Sheerness organism to 
Brachiomonas submarina. 
None of the adult vegetative specimens had the processes quite so short as 
figured by Bohlin for В. submarina, and some of the specimens agree in form 
with Bohlin's fig. 1 b of B. gracilis ; but the only alternative was to establish 
a third species intermediate in character between the two already described. 
This was inadvisable, because in the outward form of the cells, which alone 
was used in discriminating between Ж. submarina and В. gracilis, the 
Sheerness specimens exhibited much variability. The anterior region of the 
cell was never so flattened as in Bohlin's figs. 1 @ and Те of B. gracilis, and 
the posterior horn rarely so long, whereas the subhemispherical anterior 
region of the cell and the form of the posterior horn were characters in 
agreement with B. submarina. 
Length of Sheerness specimens (including horns) 15-24 и: breadth 
(including horns) 13-25 ш: length of cilia 22-29 p. 
If Bohlin's figures are correct, then the Sheerness specimens differed in 
one respect from both his species. The chloroplast never extended beyond 
the broad base of the horns, the latter always remaining clear and colourless. 
3. PHYLLOBIUM SPHAGNICOLA, sp. n. Ph. filis vegetativis longissimis, 
subcontortis et anastomosibus, inter cellulas foliorum Sphagni cretis ; cellulis 
vegetativis elongatis et subcylindricis, membrana tenuissima ; hypnosporis 
globosis vel subdepresso-globosis, membrana firma et crassa, nonnunquam 
irregulariter incrassata. Crass. fil. veget. 274-4 ш; diam. cell. hypnosp. 
18-42 и. (РІ. 21. figs. 31-35.) 
Hab. North Uist, Outer Hebrides ; on the old leaves of Sphagnum. 
In August 1904 my father collected some plants of Sphagnum in the boggy 
areas of N, Uist, Outer Hebrides, which had attracted his attention by reason 
