392 MR. G. 8. WEST ON 
portions of Sphagnum-bogs, in which situations it may sometimes 
be obtained in abundance. It is subject to considerable varia- 
tion in the character of. its smooth processes. In some forms 
they are long and gradually attenuate to the apex, which is 
bifureate (Pl. 11. figs. 5 & 12); in others there is a distinct 
constriction near the apices of the processes immediately below 
the bifurcation (Pl. 11. figs. 10 & 11); and it often happens that 
the divisions of the furcate apices are much rounded, being in 
some cases almost totally reduced (Pl. 11. figs. 6, 7, and 11). 
The latter forms are produced by rapid division of the cells. 
Some of these forms are proportionately broader than others. 
Long. e. proe. 27-3675 u; lat. e. proc. 27-48 u. 
I have examined a form with short, thick processes and widely 
furcate apices, from several localities, notably from Slieve 
Donard, Co. Down, Ireland, and from Cornwall, from which 
places pure gatherings of the form were obtained. The apices of 
the processes were bi- or trifurcate, both types being present in 
the processes of the same cell, or even of the same semicell, and 
the divisions of the apex were large and acute. Long. e. proc. 
27-29 p; lat. e. proc. 25-31 u. The processes of one semicell 
more or less alternate with those of the other, the amount of 
twist of the two semicells varying very considerably in different 
specimens. 
Some remarkable forms of this species from Ireland were 
notieed, in whieh a series of immature segments were present 
between the adult semicells (cfr. Journ. Roy. Mier. Soc. 1896, 
p. 159, t. 4. ff. 51-55). No species is known in which the 
zygospore exhibits so much variation as it does in S. brachiatum. 
14. STAURASTRUM REINSCHIT, Roy, in Scott. Nat. 1883, p.39.— 
This plant was first mentioned by Reinsch as “ Staurastrum sp." 
in his ‘ Contrib. ad Algol. et Fung.’ vol. i. Lipsie, 1875, p. 86, 
t. 17. f. 5, and was shortly afterwards described by Roy, who 
found it from several localities in Scotland, as S. Reinschii. I 
find it frequently in this country, more particularly in upland 
Sphagnum-bogs, in which situations it often occurs in quantity. 
The form of the semicells varies considerably, some being almost 
fusiform, others elliptical, and yet others almost semicircular, 
this causing a corresponding variation in the sinus. There are 
from two to four small spines at each lateral angle, and several 
others along the lateral margins, definitely arranged in one or 
