4 COCCOPHYCES. 
Size. Cells 004-007 mm.; fam. 018 mm. (Radh.), cells 
*004-:006 mm, (C). 
Rabh. Alg. iii. 24; Kirch, Alg. Schl. p. 115. 
Protococcus valgaris, Kutz. Spec. p. 199. 
Protococcus communis, Kutz. Tab. i., f. 3. 
Pleurococcus communis, Desm. Exs. 1, 1208; ii. 603. 
Hematococcus vulgaris, Hass. Alg. p. 333, t. 71, f. 5. 
Chlorococcum vulgare, Grey. Sc. Cr., Fl. No. 262. 
On the trunks of trees, moist walls,&c. Common everywhere 
throughout the year. 
“Plant of alively full green colour, spreading very extensively over 
the trunks of trees, and staining the fingers on the slightest touch, Gra- 
nules very minute, exceedingly numerous, densely aggregated, and form. 
ing an uneven surface. They are perfectly free, semi-transparent, and 
adhere together in an opposite manner by fours.” —Greville. 
Plate II. fig.1. a, natural size; 6, cells X 400 diam. 
Pleurococcus angulosus. (Corda) Meneg. Nost. t.4, f. 5. 
Cells single, or 2-4, associated (64) in families, deep green, 
nestling in greenish, rather gelatinous stratum, cell-membrane 
thick, diaphanous. 
Size. Cells :007-013 mm. (Radh.). 
Rabh. Alg. iii. 25. Kireh. Alg. Schl. p. 115. 
Protococcus angulosus, Corda in Sturm F'. ii. 18. 
Microcystis angulosa, Kutz. Linnea, viii, 374. 
Protococcus palustris, Kutz. Tab. i., t. 4, 
On the stems and leaves of aquatic plants, 
In the Kew Herbarium copy of Rabenhorst’s Alge Exsicc, No. 327, 
under this name, only Chroococcus twrgidus can be found, go that it is 
not quoted above. 
Plate 17. f.2. Cells magnified 400 diam. 
Pleurococcus (?) mucosus. adh. Alg. 111. p. 26. 
Cells very small, of variable size, single and 4-16, associated 
in globose families, scattered, or aggregated in a gelatinous 
green stratum. Cell-membrane very thin, hyaline, contents 
homogenous, decussately divided; nucleus rounded. 
Size. Cells :0023--0003 mm. (Rabh.). 
Protococcus mucosus, Kutz. Tab. i., t. 4. 
Hematococcus theriacus, Hass. Alg. p. 333, t. 78, f. 9. 
On the naked ground. 
Dr. Allmann compares its appearance to inspissated syrup. 
Plate 11. fig. 3. Cells magnified 400 diam. 
Pleurococcus Beigelii. Kiich § Rabh. 
Aérial, very small, very pale greenish, aggregated in numerous 
globose families, encircling the hair. Cell-membrane rather 
thick, colourless, contents very finely granular, sporangia con- 
taining 12-20 gonidia; nucleus globose. 
