New British Freshwater Algse. By W. and G. S. West. 161 
the specimens that have lost their cilia are slightly produced and 
emarginate. 
When the cells of the colony become large, the cilia disappear 
and the contents divide into four. The daughter-cells are at first 
round or elliptical and somewhat irregularly disposed, but they quickly 
become ovoid and arrange themselves in one plane. The cilia then 
appear and the young colony breaks away from the mother-cell and 
swims off. The colony often shows indications of breaking up^before 
the daughter-cells are mature. 
Class PR0T0C0CC0IDE.ZE. 
Order Eremobie.e. 
Genus Nephrocytium Nag. 
36. N. ecdysiscepanum sp. n. 
N. cellulis semicircularibus vel subreniformibus cum polis 
late rotundatis, ventre subrectis, diametro circiter lj-lg-plo 
longioribus; familiis e cellulis 2-8 formatis, irregulariter 
ordinatis; diametro circiter lj-plo longioribus, tegumento 
firmo hyalino, ad partem exteriorem irregulariter dissociato ; 
familiis cum in’tegumentis vetustis associatis ; contentum cellu- 
larurn granulosum. 
Long. cell. 24-26 • 5 y, lat. 13-17 y ; long. fam. 72-86 • 5 y, 
lat. 46-71 y. 
Fab. Near Goring, S.E. Oxfordshire. 
This differs from other species of the genus in having the families 
held together by the well-marked integuments, the outer portions of 
which have separated off, the families being often associated in fours 
in a somewhat fan-shaped manner. The outer part of the integument 
seems to be frequently splitting off, small families of but two cells 
often having as many as three old integuments still attached to them. 
The cells are similar in form to those of N. obesurn West ; they are 
much shorter, more robust, and straighter than those of N. Ndgelii 
Grun. 
Genus Oocystis Nag. 
37. 0. ciliata Lagerh. (Stockholm. Ped. Protoc. o Palmell., 
p. 76, t. iii. f. 33-37). 
Yar. radians n. var. PI. III. fig. 15. 
Yar. setis paullo brevioribus et in toto ambitu (18) 
distributis. 
Long. 18 y\ l it. 13' 5 y\ long. set. 13*5-17 y. 
Eab. Lindeth, Lake District. 
Order Protococcace^: (inclus. Palmellace^:). 
Genus Pleurococeus Menegh. ; Wildem. 
38. P. nimbatus Wildem. (Note sur le gen. Pleurococeus et 
sur une espece nouv., Bull, de l’Herb. Boissier, i. No. 7, 
juillet 1893, p. 342, pi. 18 ; Tetracoccus Wildemani Schmidle, 
