AnaBatIna Thwaitesi, Harv. MS. 
Has. On the muddy sides of ditches of brackish water, also floating. 
Dolgelly, Mr. Ralfs. Shorehampton, near Bristol, Mr. G. H. K. 
Thwaites. Porbury, Somerset, Mr. Broome. 
Groer. Distr. Probably in similar situations throughout Europe. 
tifully mounted specimen, communicated by G. H. K. Thwaites, 
Esq., of Bristol, to whom I am indebted for valuable notes and 
sketches of the three species now figured, without which assis- 
tance I should scarcely have ventured to publish them. I wish 
it therefore to bear the name of this gentleman, though I have 
since learned that it was originally detected by Mr. Ralfs, who 
has also, with his usual kindness, favoured me with notes and 
remarks. Mr. Thwaites observes that the connecting cell, which 
in this species is ciliated, is generally placed at or near the end 
of the filament, a peculiarity also noticed im Anabaina velutina, 
Breb., and in some others of this genus. 
B. Fig. 1. SpHa@RozyGa THWAITESII; appearance of the mass. 2. Filaments: 
magnified. 
Puatrt CXITI. C. 
SPERMOSIRA LITOREA, Kit. 
Grn. Cuar. “ Filaments slightly mucous, free, simple, cylindrical, enclosed 
in a very delicate, membranous tube. Ced/s lenticular; connecting 
cells larger, compressed.” Thw. Spores formed from the ordinary cells. 
Spermosira (Kvitz.),—from onéppa, a seed, and cepa, a chain. 
SpprmostRa litorea, Avitz. Phyc. Gen. p. 213. 
Has. In muddy brackish ditches, with the preceding. Barmouth, Rev. 7. 
Salway. Dolgelly, &c., Mr. Ralfs. Shorehampton, Mr. G. H. K. 
Thwaites. 
Goer. Distr. Probably throughout Europe, in similar situations. 
Descr. “Scarcely gelatinous, forming a deep green fleecy covering to floating 
plants, on which it occurs. Filaments of considerable diameter, nearly 
straight. Ordinary cells of a beautifully blue-green colour, very short and 
compressed, giving the filaments the appearance of an Oscillatoria ; con- 
necting cells of a pale reddish, but sometimes the plant is of an uniform dull 
green.” Thi. in litt. Spores elliptical, at length acquiring a deep brown 
colour. 
It will be seen by the figure, that the presence of a membra- 
nous tube to the filament, alone distinguishes this genus from 
Spharozygd. 
magnified. 
