SUPPLEMENT. 
To follow at page 4 — 
Pleurococcus bituminosus. (Bory. Dict. 11., 15.) 
Thallus mucous, brown-black, or pitch-colour, cells small, 
rounded angular, greenish brown, 4-8 associated in families, 
tegument scarcely broad, colourless, hyaline, indistinctly lamel- 
lose. 
Size. Cells -002 mm. ; families 0:1-"02 mm. 
Rabh. Alg. Eur. i., 28. 
Chaos bituminosus, Bory. Dict. iii., 15. 
Palmella bituminosa, Meneg. Nost. p. 56. 
Protococcus bituminosus, Kutz. Tab. Phye. i., t. 5. 
Gleocapsa bituminosa, Kutz. Spec. 224. 
On walls of damp cellars, &c. 
Plate CXXTX. fig.1. Cells and families x 400 diam. 
Pleurococcus vestitus. Reinsch. Algen. Fl. p. 56. 
Cells solitary, rarely united in small families, orange ; cell- 
membrane thick, densely invested with small hairs. 
Sizz. Cells :012--022 mm. diam. 
Rabh, Alg. Eur, i., 29. 
Acanthococcus vestitus, Lagerh, Svenska Vet. Akad. Forh., 
1883, p. 37. 
Plate CXXTX. fig. 2. Cells X 400 diam. 
Genus 14 dis. DACTYLOCOCCUS. Wag. (1849). 
Cells oblong or fusiform (at first ovate-cuspidate, then ellip- 
soid), free swimming, 2-8 associated in families, at length 
dividing and becoming single. 
Propagation by division in one direction. 
Dactylococcus De Baryanus. Reinsch. Contrib. t. x., f. 1. 
Cells broadly elliptical-oval, apex broadly rounded, base 
attenuated into a hyaline pedicel, half as long as the cell, and 
expanded at its extremity, single or twin, cell-contents intense 
green, granulose, at length divided in 3 or 4. Cell membrane 
thick. 
Size. Cells 033 x:016 mm. 
Parasitic on small aquatic crustaceans, Entomostraca, &c. 
e 
Plate CXXIX. fig. 3. u, individuals x 400 diam, ; b, two individuals 
X 720 diam. 
