Nov, 1904.] | BOTANICAL SOCIETY OF EDINBURGH. 17 
96. E. Didelta (Turp.), Ralfs. O.—Hoy. 
97. E.ampullaceum, Ralfs. O.—Kirkwall ; Hoy. 
98. E. sinuosum, Lenorm, S.—Plankton of Loch Beosetter, Bressay. 
99. E.ansatuwm, Ralfs. O.—Kirkwall; Hoy. S.—Scalloway ; Lerwick ; 
Neugles Water; Bressay ; plankton of Lochs Clickhimin and 
Trebister. 
100. E. bidentatum, Nig. O.—Kirkwall; Finstown; Stromness. S.— 
Scalloway ; Lerwick; Neugles Water; Bressay. Plankton of 
Loch Trebister, and of Loch Beosetter, Bressay, 
101. E. dubium, Nig. (EZ. lobulatum, Bréb.) O.—Kirkwall; Finstown ; 
Hoy. S.—Lerwick. 
102. E. elegans (Breb.), Kiitz. O.—Kirkwall; Hoy. S.—Bressay, in 
pools, and also in plankton of Loch Beosetter. 
103. EL. binale (Turp.), Ehrenb, O.—Kirkwall; Hoy. S.—Lerwick ; 
Scalloway. 
Forma Gutwinskii, Schmidle. O.—Near Kirkwall; Hoy. 
104, EB. denticulatum (Kirchn.), Gay. O.—Hoy. S.—Neugles Water ; 
Bressay, in pools and in the plankton of Loch Beosetter. 
105. E. montanum, sp. n. (figs. 11 and 12). 
[Cosmarium Meneghinii, Bréb., forma Boldt, in “ Bihang till 
K. Sv. Vet.-Akad. Handl.,” xiii., No. 5, 1888, p. 13, t. 1, f. 15. 
C. Meneghinii, forma Boldtii, West, in “ Journ. Roy. Micr. Soc.,” 
1892, p. 726. C. Subrevaschii, Schmidle, var. Boldtiana, Schmidle, 
in “ Flora,” 1894, p. 90, t. 6, f.8; West and G. S. West, “ Alga- 
fl. Yorks.,” 1900, p. 80.] 
E. minutum, circiter 14-plo longius quam latum, profunde 
constrictum, sinu angusto-lineari extremo subampliato; semi- 
cellule transverse oblongo-rectangulares, marginibus lateralibus 
convexis et biundulatis, undulatione majori supra undulationem 
minorem ; apicibus subprotractis, truncatis et in medio emar- 
ginatis, angulis apicalibus rectangularibus ; a latere vise ovate, 
cum tumore rotundato prope basin utrobique ; a vertice vise 
ellipticee, cum tumore rotundato in medio utrobique. Membrana 
glabra. 
Long. 20°4-27u; lat. 15°6-20u; lat. apic. 10°8-14°3u; lat. 
isthm. 3°5-4°8u ; crass. 11°5-14°5u. 
O—W. of Kirkwall. 
This small Desmid is widely distributed in the upland 
districts of the British Islands. It has been known for the last 
ten years under the name of “Cosmarium Subreinschii, var. 
Boldtiana, Schmidle,” but it is easily distinguished from Cos- 
marium Subreinschw by its larger and broader central pro- 
tuberances, by its relatively wider and more angular apices, 
and by the apical notch. After carefully considering these 
differences along with its wide distribution and constant 
characters, we think there is good reason for its specific 
separation, especially as typical C. Subreinschii is not known 
to occur in the British Islands. And not merely do we think 
this Desmid better regarded as a separate species, but the distinct 
apical emargination of the semi-cells, accompanied by a large 
central protuberance, are features which at once place it in the 
genus Huastrum. 
The specific name “ Boldtiz” could not be adopted, as it has 
already been utilised by Schmidle for another species of 
Euastrum. 
106. £. pectinatum, Bréb. 9.—Kirkwall; Hoy. S.—Scalloway. 
Var. tnevolutum, var. n. (figs. 13 and 14). 
TRANS. BOT. SOC. EDIN. VOL. XXIII. a 
