

138 SIPHOPHYCE^:. 



SIZE. Threads '006 --012 mm. diam. 



Rabh. Alg. Eur. iii., 323. Kutz. Tab. iii., t. 44, f. 1, 2. 

 Eng. Fl. v.,p. 351. Eng. Bot. ii., p. 159. Harv. Man. 126. 

 Mack. Hib. 224. Kirsch. Alg. Schl. p. 79. 



Conferva sordida, Dillw. Conf., t. 60. Johnst. Fl. Berw. ii., 

 254. ' Eng. Bot. i., t. 2303. Grev. Fl. Ed. 317. Gray Arr. 

 i., 310. 



VesicuUfera bombycina, Jenner Fl. Tunb. Wells, 186. 



In ditches, pools, &c., common. 

 Plate L1I1. jig. 4. Portions of threads of C. bomlycina X 400. 



GENUS 60. CH-ffiTOMORPHA. Kutz. (1845.) 

 Articulate thread simple, nearly equally thick, fixed by a 

 discoid, or root-like divided base, lower articulations always 

 short, before division equal, or half as long again as the diameter, 

 after division shorter than the diameter, upper articulations more 

 or less elongated. Cell-membrane thick, firm, sub -cartilagi- 

 nous, manifestly lamellose. Cell contents green, becoming by 

 age parietal, continuous, finely granulate, containing a few 

 starch granules. 



Propagation by zoogonidia. 



Chiefly marine, a few in brackish water. 



The lamination of the cell walls in this genus, and in Cladophora, 

 appeared to Braun to present some analogy to the rings in vascular 

 stems. He says, " The great number of layers which may be distin- 

 guished by suitable treatment in the cell membrane, even of plants of 

 short life (Cladophora, Botrydium, &c.), is not opposed to the assump- 

 tion that they are diurnal layers, and it is imaginable, under this 

 hypothesis, that bright and dull days, as well as the age of the cell, and 

 other circumstances, may effect important modifications in reference to 

 the formation of distinguishable layers." 



Chaetomorpha litorea. (Harv.') 



Rigid, green, crisp ate ; articulations before division one and 

 a-half times as long as the diameter, here and there swollen in 

 pairs and discoloured. 



SIZE. Threads '16 mm. diam. 



Rabh. Alg. Eur. iii., 327. 



Conferva litorea, Harv. Man. p. 208. Phyc. Britt., t. 333. 



Conferva linum, Harv. in Eng. Fl. v., 352. Wyatt, Alg. 

 Danm., No. 220. 



In salt water ditches, and estuaries. 



" Filaments 3-4 inches long or more, loosely bundled together in 

 prostrate or floating strata of considerable extent, and of a pale green 

 colour, becoming darker and duller as the season advances. Each fila- 

 ment is irregularly curled and twisted, and sometimes angularly bent. 

 The articulations are cylindrical, filled with a pale green watery endo- 



