289 
NOTES ON FRESHWATER ALGA.—II. 
By W. West, F.L.8., ann G. S. West, B.A., A.R.C.S8. 
(Prate 412.) 
Wiruin the last year or more a large number of new freshwater 
alge have been described from various parts of the world, man 
which have been given specific and varietal names on the merest 
pretext, without due consideration of previously described _alge. 
In this paper we call attention to a few of these ‘species’’ and 
‘varieties’? which have been insufficiently considered by their 
authors 
Some of our German contemporaries are rather apt to found 
“species ’’ on slight characters which are so subject to variation as 
to be useless as specific distinctions. A case in point is an article 
2 * mmermann on ‘ Das Genus Ophiocytium Naegeli” in Hed- 
Bd. xxxviii. 1899. In this paper he gives diagnoses of 
pais species and seven varieties of Ophiocytium which would be 
much better reduced to about half a dozen species. 
Not enough attention is given to accuracy of figures oie arp 
ith regard to the Desmidiacee), and in many instances the de- 
scriptions in the text do not at all correspond to the cpates on the 
pl Carelessness of observation and draughtsmanship seem to 
be characteristic of some of the recent investigators of this group of 
lants. 
i In this paper we have also attempted to clear up a few doubtful 
points in connection with certain species of Desmids, and have 
commented upon haere — interesting forms which are somewhat 
uncommon in this cou 
ZYGNEMACER. 
Desarya caLospora (Palla) nob. bid Pigs sewage calospora 
Palla in Ber. der Deutsch. Botan. Ges Jahrg. xii. 1894, 
Heft 8, pp. 228-286, t. xviii.] We have previously shown this plant 
to be a true species of Debarya; cfr. Ann. Bot. vol. xx. March, 1898, 
. 49. ve - we observed “criinly possessed perigee 
which, in is (Kitz. ) be t & G. S. West, varied mu 
hi Tierontian ne size. The zygospores were less elliptical. than 
those figured by a fas “EL veget. 18 »; long. zygosp. 22— 
26 p; lat. zygosp. 1 
Hab. Pies n near = hire N. Yorks. 
gigas cl 
2. Penrum curtum Bréb. var. oprusum, var. n. (Figs. 1-2). 
major, semicellulis lateribus ie bee subparallelis, interbos 
superioribus levissime coneavis, ee ec yeney subtruncatisque. 
Long. 41 —s lat. 20- woe! lat. isthm. 1 
Hab. Ingleton, W. ee 
This Sialcroh variety is ee larger than the typical form, with 
JournaL or Borany.—Vou. 38. [Aue. 1900.] x 
