Freshwater Algse of North Wales. By Wm. West. 305 
Genus Gomfhonema Ag. 
G. tenellum Ktz. Bettws-y-coed. 
G. dichotomum Ktz. A., Bettws-y-coed. 
G. capitatum Elirb. A. 
G. constrictum Ehrb. Do., S., A. 
G. acuminatum Ehrb. D., C., A., Llyn Idwal. 
G. intricatum Ktz. A. 
Genus Meridion Ag. 
M. circular e (Grev.) Ag. A., Llyn Ogwen. 
M. constrictum Kalfs. Llandudno. 
Genus Tabellaria Ehrb. 
T. flocculosa (Both.) Ktz. Common. 
T. ventricosa Ktz. B., C., S., Do., Llyn Ogwen. 
T. fenestrata (Lyngb.) Ktz. C., A., S., Llyn Idwal, Penmaen* 
mawr. 
Genus Tetracyclus Kalfs, 
T. lacustris Kalfs. C. 
This list, together with those records previously mentioned of 
Messrs. Cooke and Wills, enumerates 545 species and 45 varieties 
and forms. 
Note by A. W. Bennett, F.L.S. 
As Mr. West has been kind enough to send me his MS., together 
with some of his slides, perhaps I may be allowed to append the 
following notes. The neighbourhood of Capel Curig is certainly one 
of extraordinary richness, especially in Desmids, not only in species 
but in individuals; and Mr. West has worked it with great care and 
knowledge. Compared with the richest locality with which I am 
personally acquainted, Skelwith in Westmoreland, it is certainly con- 
siderably more productive. It may help to give an idea of the extent 
to which Mr. West’s paper enlarges our knowledge of the geographical 
distribution of Desmids, if I append the following list of species found 
by him (in addition to those marked with an asterisk) which have no 
locality in Great Britain assigned to them in Dr. Cooke’s work, 
although some of them have since been found in other spots by my- 
self or other observers: — Gonatozygon Brebissonii, Sphmrozosma 
pulchellum, Docidium coronatum, Closterium obtusum, praelongum, 
gracile, Cynthia, Kiitzingii, and subulatum, Penium spiro-striolatum 
and Mooreanum, Cylindrocystis diplospora, Spirotaenia truncata,Micras- 
terias mucronata, Euastrum venustum, Cosmarium homalodermum, 
truncatellum, exiguum, Regnesii, orthostichum, quinarium, and hexa- 
lobum, Calocylindrus palangula,Xanthidium antilopeum, Arthrodesmus 
189U z 
