22 
161. 
162. 
163. 
164, 
176. 
1. 
178. 
179. 
180. 
181. 
C. 
0. 
C. 
C. 
QD 
TRANSACTIONS AND PROCEEDINGS OF THE [ Sess. LXIX. 
speciosum, Lund. 0.—Hoy. Plankton of Loch Kirbister. S.— 
Scalloway ; Bressay. 
subspeciosum, Nordst. 0.—Kirkwall. S.—Scalloway. Plankton 
of Loch Beosetter, Bressay. 
globoswm, Buln. S.—Lerwick ; Bressay. 
subaectowm (Lagerh.), Racib., in “ Rozpraw Wydz. matem.-przy. 
Akad. Umiej. Krakow,” xxii., 1892, p. 385, t. 6, f. 24. 
[C. globosum, Buln., subsp. subarctowm, Lagerh., in Wittr., and 
Nordst, “ Alg. Exsic.,” fase. 21, no. 567, 1883; Nordst, in 
“ Ofvers. af K. Vet.-Akad. Forh.,” 1885, no. 3, p. 9, t. 7, f. 5.] 
Forma punctata (fig. 24). 
Forma membrana distincte et irregulariter punctata. 
Long. 16-19u; lat. 13°5-16«; lat. isthm. 8°6-10°54; crass. 
9-10u. 
S.—Plankton of Loch Beosetter, Bressay. 
C. affine, Racib., is a very close ally of C. swbarctowm, and would 
perhaps be better considered as one of the forms of it. The 
Desmid described and figured by Schmidle as ‘“ Dysphinctiwm 
affine, Racib., forma. major” (vide “ Engl. Botan. Jahrbiich,” 
Bd. xxvi., 1898, p. 20, t. 4, f. 16), lends further support to this 
view. 
. pseudarctoum, Nordst. O.—Hoy. S.—Plankton of Loch Asta. 
. Regnesti, Reinsch. S.—Near Scalloway. 
. crenatum, Ralfs. O.—Hoy. S.—Lerwick ; Bressay. 
quadratum, Ralfs. O.— Kirkwall; Hoy. S.— Lerwick ; 
Sealloway. 
', anceps, Lund, 0O.—W. of Kirkwall ; Hoy. 
. pseudexiguum, Racib, S.—Lerwick. 
. obliquum, Nordst. O.—W. of Kirkwall. 
' pygmeum, Arch. [C. minutissimum, Heimerl; C. Heimerliz, 
W.and G. 8. West.] O.—Kirkwall; Finstown ; Hoy (summit 
of Ward Hill). 
. Sphagnicolum, W. and G. S. West. O.—Finstown. 
. abbreviatum, Racib. O.—Finstown. S.—Plankton of Loch Asta, 
and also of Loch Beosetter, Bressay. 
. quadrimamillatum, W. and G. S. West. Long. 25-27 ; lat. 25- 
27u ; lat. isthm. 74. S.—Bressay, in a ditch. 
This species has only previously been recorded from near the 
Lizard, Cornwall. Hence it must be regarded as a western 
type. 
. Regnellii, Wille. O.—Kirkwall. S.—Lerwick ; Bressay. 
. Meneghinii, Bréb. O.—Kirkwall. Plankton of Lech Kirbister. 
S.—Lerwick. 
Forma octangularis, Wille. O.—Kirkwall. §.—Lerwick ; 
Scalloway ; Neugles Water ; Bressay. Plankton of Lochs Asta 
and Sandy. 
. angulosum, Bréb., var. concinnum (Rabenh.), W. and G. S. West. 
0.—Kirkwall ; Hoy. S.—Plankton of Loch Asta. 
trilobulatum, Reinsch. O.—Hoy. S.—Near Scalloway. 
difficile, Liitkem. O.—Kirkwall; Hoy. S.—Scalloway. 
Var. subleve, Liitkem. O.—Kirkwall; Hoy. S.—Scalloway. 
Plankton of Loch Beosetter, Bressay. 
leve, Rabenh., “Flor. Europ. Algar. IIL.” 1868, p. 161; 
Nordst, in “ Ofvers. af K. Vet.-Akad. Foérh.,” 1876, no. 6, t. 12, 
f. 4; G. S. West, in “Journ. Linn. Soc.,’ bot. xxxiv., 1899, 
p. 386, t. 10, f. 1-6. 
O.—Hoy. S.—Lerwick. 
