284 MR. G. S, WEST ON SOME CRITICAL GREEN ALGE. 
of their peculiar appearance. The plants were old, with withered, bieached 
leaves, on which were dotted here and there irregular blotches of a vivid 
green colour, 
А closer examination of the leaves showed them to be studded with the 
dark green cells of an epiphytic Alga. Some of the specimens were dried 
and others were preserved in 2 per cent. formalin, and on further investi- 
gation the epiphyte has proved to be an undescribed species of the genus 
Phyllobium. 
The two previously known species of this genus, Phyllobium dimorphum, 
Klebs, and P. incertum, Klebs ', were discovered on dead leayes—the former 
on Lysimachia Nummularia, Ajuga, Chlora, &e., and the latter on the leaves 
of Carer. This is the first recorded instance of а Phyllobium occurring on 
the leaves of Sphagnum, and I have named it Phyllobium sphagnicola. 
The bright green cells studding the exterior of the old Sphagnum-leaves 
are the resting-cells, and occur either scattered or in irregular clusters. The 
cell-wall is often irregularly thickened, and not infrequently produced out at 
some indefinite point into a curved beak-like projection (fig. 33). All the 
thickened parts of the cell-wall show a marked Jamellation, These green 
cells are attached at the base to the vegetative thallus, consisting of slender 
branched threads, anastomosing and ramifying over the entire leaf. Each 
resting-cell is attached to one or sometimes two of the vegetative threads, 
and the wall in the region of attachment is generally much thickened and 
lamellose. The adult vegetative threads are destitute of protoplasts or of 
chlorophyll, are much branched, and distinctly but distantly septate. These 
threads follow a very irregular course, commonly passing through the leaf by 
means of the perforations in the large hyaline cells. 
As the specimens were preserved, the formation of gametes and zoogonidia 
could not be observed. 
The green resting-cells of Phyllobium sphagnicola are smaller and more 
rounded than those of P. dimorphum, and their attachment to the vegetative 
filaments is more basal than lateral. The threads composing the vegetative 
part of the thallus are also profusely developed, possibly owing to the ease 
with which they can traverse the large hyaline cells of the Sphagnum- 
leaf. 
1. KIRCHNERIELLA SUBSOLITARLA. sp. n. A. cellulis minutis, obesis, 
arcuatissimis, polis obtusis vel rarissime subacutis. кере magnitudinis 
inæqualis ; cellulis plerumque solitariis vel in colonii« parvis e cellulis 
2-4 constitutis, coloniis non mucosis. Diam. max. cell. 6-7 ш: crass. cell. 
2:9-32 м; crass. colon. 4 cell. 10-15 p. (РІ. 20. figs. 20-30.) 
Hab. Studley Park, Warwickshire ; in small pond. 
' G. Klebs, “ Beiträge zur Kenntnis niederer Algenformen," in Bot. Zeit. xxxix. (1881) 
рр. 268-272, 281-290, 297-300, 252-332; t. 3. ff. 29-37 ; t. 4. f 38-49, 50-54. 
