Nov 
1904. | BOTANICAL SOCIETY OF EDINBURGH. 25 
The forms of this species noticed from the Shetlands were a 
little more inflated than usual, and the granulation was somewhat 
finer. The minute denticulations or spines at the angles were 
variable in length, and one or two were present at each angle 
(vide W. and Gris: West, l.c., p. 46). In the vertical view the 
sides were straight or very slightly concave. 
Long. 29-33u ; lat. sine mucr. 25-294 ; cum muer, 27-34, ; 
lat. isthm. 9-12°5p. 
S.—Plankton of Loch Asta, 
203. S. aciculiferum (West), Anders. O.— Hoy. 
204. S. furcigerum, Bréb. O.—Finstown. 
205. S. Reinschir, Roy. O.—Hoy. 
206. S. teliferum, Ralfs. O—Plankton of Loch Kirbister. S.—Bressay, 
in pools, and also in the plankton of Loch Beosetter, 
207. S. Saxonicum, Buln. S.—Plankton of Loch Trebister. 
208. S. pilosum (Nag), Arch. S.—Bressay. Plankton of Loch 
Trebister. 
209. S. hirsutum (Ehrenb.), Bréb. O.—Kirkwall. S.—Near Lerwick ; 
Scalloway. 
210. S. eraswum, Bréb. S.—Plankton of Loch Brindister, and also of 
Loch Beosetter, Bressay. 
211. S. muticwm, Bréb. O.—Kirkwall. S.—Neugles Water; Bressay. 
212. S. retusum, Turn., in “ Kongl. Sv. Vet. -Akad. Handl.,” XXV., 1893, 
no. 5, p. 104, t. 13, f. 13. 
Var. boreale, var. n. (fig. 30). 
Var. minor, marginibus lateralibus semicellularum convexis, 
apicibus levissime retusis ; semicellulee a vertice visee angulis late 
obtusis, lateribus subrectis vel levissime retusis ; membrana glabra. 
Long. 17°5-19u ; lat. 16°2-17 5y ; lat. isthm. 554. O.—Hoy. 
S.—In bog near Lerwick. 
213. S. orbiculare (Ehrenb.), Ralfs. O.—Kirkwall; Finstown. S.— 
Lerwick ; Scalloway ; Bressay. 
Var. depressum, Roy and Biss. O.—Finstown. S.—Plankton 
of Loch Asta. 
214. S. Bieneanwm, Rabenh. O.—Finstown. 
215. S. Sebtricum, Borge. S.—Bressay. 
The typical form of this species has not previously been recorded 
from the British Islands. 
216. S. dilatatum, Ehrenb. O.—Kirkwall. 
Var. obtusilobum, De Not. S.—Neugles Water; Bressay, in 
ditches, and also in the plankton of Loch Beosetter. 
217. S. alternans, Bréb. _ 8. 
218. S. punctulatum, Bréb. O.—Kirkwall ; Hoy: ; S.— Lerwick ; 
Scalloway ; Bressay. Plankton of Loch Trebister. 
219. S. pygmeum, Bréb. O.—Hoy. S.—Lerwick. 
220, S. Kjellmanii, Wille. Long. 48u; lat. 31lu; lat. isthm. 14. S.— 
Bressay, in a ditch. 
221. S. muricatum, Bréb. S.—Near Scalloway. 
222. S. Meriant, Reinsch. 0. —Hoy. S.—Near Scalloway. 
223. S. brachiatum, Ralfs. S.—Plankton of a Beosetter, Bressay. 
224. S. tetracerum, Ralfs. 0. —Kirkwall. —Neugles Water ; Loch 
Brindister. Plankton of Loch Asta, 
Forma trigona, Lund. S.—Bressay. 
Var. evolutum, var. n. (fig. 31). 
Var. processibus cellularum longioribus ; semicellulis a vertice 
visis triangularibus, lateribus convexis, angulis in processus 
longos productis. 
