and Genera of Chlorospermous Algse. 415 



union of the endochrome of two cells, which at length become 

 divided crosswise into four spores. 



* The filaments parallel. 



1. Thwaitesia. (Berkeley, Crypt. 152. f. 39.) 



** Filaments bent, united at the angle. 



2. Mesocarpus. (Payen, Crypt. 26. f. 114; H assail, t. 42. f. 1.) 



3. Staurocarpus. (Payen, Crypt. 26. f. 113 ; Hassall, t. 47. f. 1.) 



Fam. 3. (Edogoniacese. 



The frond rooted, simple, articulated, thread-like, composed of 

 a series of equal cells filled with endochrome ; some of the cells 

 eventually becoming dilated and swollen. Spore formed by the 

 division of the endochrome of a fertile cell ; the cell separates 

 into two half-cells by a transverse partition. The zoospore is 

 formed in one half; the other half lengthens to its proper size, 

 and divides again ; and this process is often repeated. (Thwaites, 

 Ann. Nat. Hist. xvii. 333 ; Berk. Crypt, p. 151. f. 38.) 



1. (Eclogonium. (Vesicularia capillaris, Hassall, t. 50. f. 1, 2.) 



" The divided portion of the endochrome which does not bear 

 a spore swells, increases in length, is itself divided, and the 

 posterior half becomes fertile ; and this process may be repeated 

 till a chain of spores is formed. The endochrome in the fertile 

 half-cell, whether mixed with that of the neighbouring cell or 

 not, contracts into a globular or elliptical mass, acquires a di- 

 stinct envelope, most probably after impregnation ; and this forms 

 a spore. In some instances these spores are perfectly quiet, but 

 in others they have ciliated appendages at one extremity, by 

 means of which they move about with an apparently spontaneous 

 motion. The spores after a time become attached at one end by 

 two or three root-like processes, the endochrome divides, and 

 new threads are formed. 



" The upper cells of the antheridium of (Edogonium produce 

 two elliptical bodies, which pass into the cavity of the spore-cell 

 and there effect the impregnation of the spores. The antheridia 

 are first formed within special cells, from which they escape and 

 move about by means of a coronet of cilia, till they fix themselves 

 upon the spore-cell/' (Pringsheim, in Berkeley, Crypt, p. 565.) 



Fam. 4. BuTbochaetaceae. 



" Threads articulate, branched ; fertile branchlets bulb-shaped, 

 surmounted by a long inarticulate hair-like point. Endochrome 

 apparently impregnated by bodies provided in little antheridia 

 seated on the wall of the fertile cells, dividing at length into 

 four ovate zoospores." (Berkeley, Crypt, p. 156.) 



