and Genera of Chlorospermous Algse. 411 



gelatine, attached or, more rarely, free. Cells elongate, mostly 

 uniform in size. Endochrome filling the cavity of the cells. 

 Zoospores minute, undefined, numerous in each cell. 



* The stem branched. 



1. Cladophora. 



** The stem unbranched. 



" A large quantity of Confervacece consist of simple unbranched 

 articulate threads, increasing in length by constant division of 

 the endochrome, and propagated either by the rupture of the 

 thread or by active granules formed within these articulations, 

 and escaping by a regular aperture." (Berkeley, Crypt, p. 133.) 



2. Chcetomorpha. (C. melaginium, Harvey, Ph. Brit. t. 99 a.) 



3. Hormotrichium. {H. Young anum, Harvey, Ph. Brit. t. 328.) 



4. Rhizoclonium. (R. riparium, Harvey, Ph. Brit. t. 238.) 



The following genera, having a frond of filmy network formed 

 of dichotomously-branched anastomosing filaments, should, per- 

 haps, be arranged in this family. 



5. Microdictyon. (M. Agardhianum, Harvey, Ner. Aust. i. t. 50.) 



6. Talarodictyon. (Payen, Crypt. 24.) 



7. Anadynomene. {A. flabellata, Harvey, Ner. Bor.-Am. 49. 



t.4lA.) 



See also Cladophoral anastomosans,Havvey,Nev. Aust. ii. t. 111. 



Suborder III. Solenomorpha. 



The cells isolated, more or less uniform, often forming a 

 beaded series, contained in an inarticulate tubular sheath or in 

 a gelatinous frond formed of the more or less coalesced tubular 

 sheaths. The threads are simple, or only appear branched from 

 apposition, and contain the zoospores. The cells or series of 

 cells sometimes divide longitudinally. 



Fam. 1. Oscillatoriaceae. 



The cells compressed, disk-like, very short ; they multiply by 

 transverse division. Threads articulated, simple, or branched 

 by the division of a metamorphosed cell, more rarely by the 

 protrusion of the central cord consequent on the rupture of its 

 outer coat. Cells generally very narrow. Propagation (where 

 the mode of fructification has been ascertained) by means of 

 zoospores. 



" It was once supposed that their endochromes were totally 

 different from those of Confervce, consisting merely of circular 

 disks filling up a common tube, and finally expelled from it. 

 There is, however, no doubt that they are of the same nature as 



