76 PROCEEDINGS OF SOCIETIES. 
Staurastrum orbiculare (Hhr.), not common. 
ui tumidum (Bred.), rare [“‘ Seechon” mountain ]. 
.. margaritaceum (/.), rare. 
E punctulatum (Bred.), not uncommon. 
cs hirsutum (Z/r.), common. 
55 teliferum ( ), rare. 
¥ polymorphum (Sred.), not uncommon. 
Se tricorne (Bred.), common. 
A controversum (Sved.), not uncommon. 
hh paradoxum (Meyen), Bs 
f6 brachiatum ( ), rare. 
os alternans (Breb.), ,, 
a asperum 6 (Breé.), ,, 
[I have met with a form of Staurastrum bearing some 
resemblance to S. spinosuwm, or rather between that species 
and §. avicula. 'The spines at the angles are forked to the 
base, and not merely at the extremities, and the intermediate 
spines are smaller than S. spizosum. The form agrees much 
better with the figure of S. avicula, provided that species 
had intermediate spines, than with that of S. spizosum. It 
is not uncommon, according to my experience, in the district 
to which this list appertains. | 
Didymocladon furcigerus a (Bred.), rare. [Slow stream between Round- 
wood and Devil’s Glen. May be more common, however. | 
Tetmemorus Brebissonii (M/exegh.), common. 
5 granulatus (Breb.), very common, 
Penium margaritaceum (Z/7.) not uncommon. 
»  eylindrus (Zhr.), ” 
»  digitus (Zhr.), very common. 
»  Brebissonii (Menegh.) ,, 
»  Closterioides ( ), rare. 
Docidium nodulosum (Bred.), not uncommon. 
is truncatum (Bred.), 
2 clavatum (Kutz.), a 
Ehrenbergii ( ), common. 
» asperum (Bveb.), rare. [Should a master-hand ever propose the 
erection of a new genus for the reception of this species, or its 
removal from Docidium, the step would meet with my approval. 
To my mind it is zo¢ a Docidium: it entirely wants the charac- 
teristic constriction of that genus, and I have looked carefully, 
but in vain, as Mr. Ralfs did, for terminal moving globules. I 
have found occasionally three or more individuals adhering end 
to end, like a filamentous conferva, with extremely long cells. 
The specimens I have met with were rather more dilated at the 
ends than is represented in Ralfs’ figures. ] 
Closterium lunula (Mziller), common. [This is a favorable species for 
observing the circulation. It is not, however, like that phe- 
nomenon in other vegetable cells, the current being here of 
a very fitful and irregular character. It possibly bears some 
relation to the movement of the free granules at the ends of 
the frond. I have scarcely ever found any difficulty in de- 
tecting it. ] 
3? 
* lanceolatum (Aw¢z.), not common. 
3 acerosum (Schrank), not uncommon. 
i turgidum (Z.), ‘5 
Bs Leibleinii (Awéz.), common. 
” Diane (Hhr.), 
22 
