Nov 
230 
231 
232. 
: 1904. | BOTANICAL SOCIETY OF EDINBURGH. 
bo 
~I 
. S. crenulatum (Nig.), Delp. O.—W. of Kirkwall. 
. S. gracile, Ralfs. O.—Plankton of Loch Kirbister. S. 
Lerwick ; 
Scalloway. Plankton of Loch Clickhimin, Neugles Water, and 
of Loch Beosetter, Bressay. 
Var. nanum, Wille. O.—-Kirkwall. 
. boreale, sp. n. (fig. 25). 
S. parvum, circiter 1}3-plo latius quam longum (cum pro- 
cessibus), subprofunde constrictum ; semicellule subeyathi- 
formes, angulis superioribus in processus longos subhorizontaliter 
dispositos (vel levissime divergentes) productis, processibus cum 
annulis 4 denticulorum preditis, apicibus processuum trispinatis, 
apicibus semicellularum leviter subprotractis denticulatis et 
subrectis, ad basin extremum semicellularum cum annulo den- 
ticolorum 11-13 (viso 6—7) ; a vertice vise triangulares, angulis in 
processus sublongos denticulatos productis, lateribus subrectis 
cum verrucis bidenticulatis 3, intra marginem unumquemque 
verrucis emarginatis 3 ornatis. 
Long. 27-29; lat. cum proc. 43-46u ; lat. isthm. 
S.—Plankton of Loch Asta. 
This small and elegant Strawrastrum occurred in considerable 
quantity in the plankton of Loch Asta, and it is not very closely 
allied to any other British species of the genus. It should, 
perhaps, be compared with S. Burmense, Turn., and S. galeatum, 
Turn. (vide W. and G. 8. West, in “Trans. Linn, Soc.,” bot. ser. 
2, vi., p. 190, t. 22, f. 19). 
t 
3-8u. 
233. S. paradoxwm, Meyen. S.—Scalloway. Plankton of Lochs Brin- 
dister, Trebister, and Sandy; also of Neugles Water, and of 
Loch Beosetter, Bressay. 
From Loch Sandy the specimens were very variable with 
regard to the length of the processes. Long. sine proc, 22—28u ; 
cum proc. 36—42u ; lat. cum proc. 44-61; lat. isthm. 6x (figs. 34 
and 35). 
From Loch Trebister some forms were noticed almost identical 
with others seen from Loch Laxadale, Harris, Outer Hebrides 
(vide W. and G.S. West, in “ Journ. Linn. Soc.,” bot. xxxv., 1908, 
p- 548, t. 18, f. 4). Long. sine proc. 274, cum proc. 39y ; lat. 
cum proc, 44-49u; lat. isthm. 9u. The specimens were quad- 
rangular, and a little smaller than those previously seen from 
Harris (fig. 33). 
234. S. pseudopelagicum, W. and G, 8S. West. 0.—Plankton of Loch 
Kirbister. 
235. S. Manfeldtzi, Delp. 
Long. 47-5l«; lat. cum proc. 64-694; lat. isthm. 14u 
(fig. 26). 
S.—Plankton of Lochs Sandy and Trebister, and also of Loch 
Beosetter, Bressay. 
This species was particularly abundant from Loch Sandy, 
occurring in prodigious quantity amongst Asterionella formosa 
and Melosira granulata, The specimens agreed very well with 
Delponte’s Italian ones, but the emarginate warts at the apex 
showed greater regularity. In the vertical view the sides of the 
semi-cells are smooth, and the margins of the processes are only 
gently undulate. 
A few scattered granules were present at the base of each 
semi-cell, and there was a very slight basal swelling. Vide 
W. and G. S. West, in “ Trans, Roy. Irish Acad.,” xxxii., sect. B., 
1902, p. 56, t. 1, f. 29). 
