152 
Transactions of the Society. 
Hab. Near Goring, S.E. Oxfordshire. In great abundance 
with zygospores. 
This little species differs sufficiently from allied species, such as 
Cl. yarvulum Nag., CL Venus Kiitz., Cl. calosjoorum Wittr., &c., in 
its curvature and in the peculiar form of the zygospore, which is often 
twisted, one half being turned through an angle of about 90°. 
8. C. calosporum Wittr. (Anteck. Skandin. Desm., p. 23, f. 11). 
Forma major. PI. III. figs. 25, 2G. 
Lat. 14-17 yu. ; apicibus inter se distantibus circiter 161 yu, ; 
diam. zygosp. sine proc. 29 '5-37 yu, ; cum proc. 38-51 /x. 
Hah. Goring, S.E. Oxfordshire. 
This beautiful little species has not been previously recorded with 
zygospores from England, but Archer has found it in Ireland, and 
Roy and Bisset in Scotland. The colourless conical processes of the 
zygospore in our examples were distinctly longer than those observed 
by Wittrock. 
Boy a g. n. 
Cellulae levissime arcuatae, perfecte cylindrical baud attenuatae, 
utroque polo subtruncatae vel obtuso-rotundatae ; contentum chloro- 
phyllosum cellularum prope apices attingens, in medio absens ad latus 
unum in spatio semicirculari ; locellus apicalis nullus, igitur sine cor- 
pusculis moventibus ; pyrenoides 4-6 in una serie axillari dispositi ; 
membrana acliroa glabra. 
9. R. obtusa (Breb.) nob. f Closterium obtusum Breb. Liste Desm., 
p. 154, t. ii. f. 46 ; Rabh. Flor. Europ. Algar. iii. p. 124 ; 
Cooke, Brit. Desm., p. 19, pi. x. f. 4 ; Wolle, Desm. U.S.A., 
p. 38, pi. vi. f. 1.] 
Var. Montana var. n. PL III. figs. 23, 24. 
[Closterium ohtusum Breb. f. apicibus subtruncatis, 
West, Alg. of Eng. Lake Distr., Journ. Roy. Micr. 
Soc., Dec. 1892, p. 719, PI. IX. fig. 13.] 
Var. minor, apicibus distincte subtruncatis, membrana 
tenuissima et glabra. Forsan sit species propria. 
Long. 48-81 fx ; lat. 5 * 5-6 /x. 
Hah. Fairly abundant, along with Penium cruciferum 
de Bary, in washings of Bhacomitrium aciculare , 
from constantly dripping rocks, Baildon Moor, W. 
Yorks. Also in profusion amongst Mougeotia 
scalaris Hass, on dripping rocks, Ogden Clough, 
W. Yorks. Scarce, amongst other algae on wet 
rocks, Helvellyn, Westmoreland. 
The entire absence of attenuation in the slightly bent cells, the 
position of the nucleus in the peculiar semicircular excavation of the 
chlorophyll, and the absence of an apical locellus sufficiently separate 
this genus from Closterium. We have much pleasure in naming it 
