CONFERVACEJS. 135 



FAMILY III. OONFERVAOB^B. 



Threads articulate, either simple or branched, vegetation 

 terminal, unlimited. Articulations more or less elongated, 

 rarely abbreviated, now and then shorter than the diameter, 

 cylindrical, rarely swollen. Cell membrane sometimes mani- 

 festly lamellose. Chlorophyllovse mass granulate, containing 

 starch granules, effused, parietal, or sometimes contracted in the 

 centre of the cell. 



Vegetation by the repeated division of the primordial utricle 

 in one direction. 



Propagation by zoogonidia. 



GENUS 58. MICROS FOR A. Thur. (1851.) 



Articulate thread simple. Chlorophyllose mass at first 

 parietal, afterwards contracted in the centre. All articulations 

 fertile. 



Propagation by zoogonidia. Zoogonidia arising from a 

 simultaneous division of the cell contents, small, numerous, 

 ovate-elliptical, cuspidate and colourless at one end, usually 

 furnished with two, rarely 3 to 4, cilia, escaping by rupture of 

 the cell. 



Microspora fugacissima. (Ag. Syst. p 43.) 



Pale green, or yellowish green, articulations before division 

 4 to 5 times as long as their diameter, after division about 2 to 

 2-g- times as long, not constricted at the joints. 



SIZE. Cells 0085-'01 mm. diani. 



Eabh. Alg. Eur. iii., 321. 



Conferva fugacissima, Grev. Fl. Ed. 317. Gray AIT. i., 310. 

 Kirsch. Alg. Schl. p. 80. 



In ditches. 



Plate LIII. fg. 1. Portions of threads of M. fugacissima X 300 

 diam. 



XVXicrospoxa vulgaxis. Rahh. Alg. Eur. in., 321. 



Bright green, articulations 2 to 3J times as long as the 

 diameter. 



SIZE. Threads '012 mm. diameter. 



Conferva bombycina incequalis, Kutz. Tab. iii., t. 44, f. 3. 



Microspora bombycina, Thuret. Rech. p, 12. 



Conferva vulgariSj Kirsch. Alg. Schl. p. 79. 



In ditches and pools. 



Plate LIII. Jig 2. Portions of threads of M. vulgaris X 300 diam. 



W 



