PROTOCOCCACEA. 47 
The family (or ccenobium) in this genus is solid, and not hollow as in 
Celastrum, composed of wedge-shaped or heart-shaped cells, somewhat 
compressed and united into globose families, the narrow ends meeting 
in the centre, with the outer margin emarginate or divided. 
Sorastrum spinulosum. Wig. Einz. Alg. p. 99. 
Cenobium spinulose, cells wedge-shaped, apex slightly 
emarginate, angles obtusely rounded, bi-spinulose. 
Size. Coenobium to ‘04 mm. diam. 
Archer Micr. Journ., 1866, p. 124, Pritch. Infus. t. 1, f. 
56-58. Rabh. Alg. ili, 81. Reinsch Algenflor. p. 86, t. 5, f. 6. 
In stagnant water. 
Plate XIX. fig. 1. a, 6, families magnified 400 diameters; c, side 
view of cell ; d, frout view of same. 
Genus 33. SELENASTRUM. Reinsch. 
Cells semilunate, joined together by the middle of the convex 
margin, in families of 4-8, regularly disposed. Propagation 
unknown.—Reinsch Algenfior. frank. p. 64. 
Selenastrum Bibraianum. Reinsch Algenflora p. 64. 
Cells semilunate, with the cusps either expanded or curved 
inwards ; minor families constituted of four cells in pairs, major 
families of these combined in more or less spherical masses. 
Size. Cells :016--023 mm. long Xx ‘005-008 mm. diam.; 
minor families -023-'031 mm. diam. 
In moor pools. 
Plate XIX. jig. 3. a, families magnified 400 diameters; b, pair of 
cells magnified 1000 diameters. 
Sub-Family 9. CHARACIEA. 
Cells always innate, often distinctly stipitate, variable in 
form; cell-membrane delicate, growing thicker with age (then 
double membrane visible); cell-contents bright green, homo- 
genous, afterwards always granular, with one starch granule, 
ultimately divided. Propagation by repeated binary division of 
the cytioplasm, resulting in more or less numerous biciliate zoo- 
gonidia.—Radh. Alg. Eur, iii. 81. 
Genus 34. CHARACIUM. Braun. (1847.) 
Cells oblong, ovate, pyriform, fusiform, rarely acicular or 
subglobose, equal or oblique, erect or inclined, attenuated at 
the base in a hyaline stem. Cell-contents green, homogenous 
or granular, zoogonidia, succeeding division of the cytioplasm, 
more or less numerous, occupying the whole of the cell, at 
length greatly agitated, escaping by a lateral (rarely terminal) 
rupture, oblong, with two vibratile cilia—Braun Unicel. Alg. 
p. 29. 
