a i i tN iii i i 
THE ALGA-FLORA OF CAMBRIDGESHIRE. 107 
I follow Rabenhorst on: et 2 Algar. iii. 68) in the inclusion 
of Sciadium A. Br. in the genus Ophiocytium. The former consists 
merely of an aggregate of individuals of the sakioes genus, and in 
— cases the cells composing this aggregate are coiled quite a 
m 1 Ophiocytium, a fact which still farther 
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coiling of the cells in specimens of 0. Arbuscula from Westport, 
Co. Galway, Ireland, equal in extent to that found in O. cochleare. 
Fam. CHRooLEPIDACE®. 
8. Micrornamnion Kirzineianum Nag. 5. Wicken Fen: Aug. 
1908, amongst Chara hispida. 
49. Pilinia stagnalis, sp. n. (Pl. 394, figs. 6-9). P. crustacea, 
sordide viridis; csspitibus densissime ageregatis, own 500 
altis; filam entis erectis fasciculatis brevibus, hine inde breviter 
ramosis ; filamentis procumbentibus in stratum cellularum pseudo- 
parenchym aticum concretis; cellulis filamentorum erectorum sub- 
cylindricis, diametro 2-6- plo. longioribus, a lis terminalibus 
subtumidis, inflatis, i ulis filamentorum 
procumbentium ese paullo minoribus ine: ioribusque, dia- 
metro equalibus vel duplo longioribus ; m ana cellularum firma 
subpyriformibus. ers i Biase 16-25 in crass. cell. fil. 
procumb. 16-31 p; crass. capcatdn mid en 
7. The Washes, aah forming a tough dull green stratum on 
shells of Limnea pere. 
This genus was atabhiahed by Kitzing in 1843, and up to the 
present it includes only two known species, P. rimosa Kitz. and 
P.? diluta Wood. The former is a small marine species found on 
wood, stones, and shells on the shores of continental Europe and 
N. America, and the latter is a freshwater species from Pennsylvania. 
P. stagnalis is distinguished from P. rimosa by its much larger size, 
its less branched filaments with args ively taiiber cells, and by 
its freshwater habit. From P.? diluta it is distinguish hed by the 
different character of its ata the larger size of the cells, and by 
the swollen terminal cells of the less branched filam 
branching is also shown in some much larger plants belonging to 
Cladophoracew (cfr. Schmidle in Engler’s Botan. Jahrbiich. 1896, 
Bd. 23, 263, cum f. 5, 6). 
Fam. CLapopHoRrAcER. 
50. ee orispata (Roth) Kiitz. age Dernford Fen, 1 pile 
S. of Shelford. Comberton ; ; Wim a aes 4. Pond n 
Girton. 6. Roawell Pits, Ely. 7. Near ae 
