COLLECTED IN THE SOUTH ORKNEYs, 333 
Merismopedia) ; dispositio cellularum in partibus interioribus familie 
investigari non potest, sed dispositio regularis verisimile est. 
Diam. fam. = 13-20 ; diam. cell. fere 0*7 р. 
"amples 11 and 14, common. 
In view of the very minute size of the cells and their dense aggregation, 
it has been impossible to determire exactly their arrangement in the interior 
of the solid colonies, but focussing in different planes seems to show that the 
sume regular arrangement obtains all through. Jt is possible that this 
species belongs to the genus Енсархх, described by Clements and Shantz 
(Minnesota Bot. Studies, iv. 1909, p. 134) : but in the latter genus the 
colonies are described as cubical, which in no way applies to the rather 
irregular colonies of M. merismopedioides, The colonies closely resemble 
those of a Microcystis in all except the regular arrangement of the minute 
cells. 
41. Charurocystis RETICULATA (Lemm.), Forti, Sylloge Mycophycearum, 
1907, p. 96. 
Sample 10, rather rare. 
42. GOMPHOSPHÆRIA APONINA, Küt:. Tub. Piye. i t. 31. fig. 3; Rabenhorst, 
Fl. Europ. Alg. iii. 1865, p. 56. 
Sample 11, rare. 
43. CŒELOSPHÆKIUM  KÜTZINGIANUM, Naeg. Gatt. асе И. Aly. 1849, p. 54, 
t. lc. 
Sample 11, rare. 
44. MERISMOPEDIA GLAUCUM. (Ehrb.), Naeg. Gatt. einzell. Aly. 1849. p. 55, 
t. Lp. fig. Т. 
Sample 11, rather rare. 
45. MERISMOPEDIA TENUISSIMUM, Lemm. Beitr. 2. Kenntn. de Planktonalgen, 
in Bot. Centralbl, 1898, р. 154. 
Sample 10, rare. 
OSCILLATORLIACI.E. 
46. OSCILLATORIA BREVIS, АР. ; Gomont, Oseillurices, in Ann, Sci. Nat. 
Bot. sér. 7, xvi. 1892, p. 249, pl. 7. figs. 14-15. 
"ample 10, rather rare. 
47. OsciLLATORIA SPLENDIDA, (Grer.: Gomont, loc, cit. p. 244, pl. T. 
figs. 1-8. 
Sample 10, rather rare. 
