136 Bibliographical Notices. 



primary divisions are: — 1, those Cladophoroi which are attached 

 when young, and afterwards float freely in the foi-m of tufts ; 2, 

 those which are always attached ; and, 3, those which are at first 

 attached, and afterwards form globular masses which are often 

 free. This last division includes Cladophora cef/a(/ropiIa. It 

 is doubtful whether this third division c^n be maintained. The 

 eight forms of Cladophorn mjagropila here described aU grow in 

 still water, and may possibly be only forms of C. (jloineraUi, modi- 

 fied by their place of growth. Professor Henfrey* considered Cla- 

 dophora (cgagropila to be identical with C. (jlomerata; and Mr. 

 Hassall, in his ' Freshwater Algte,' took tlie same view with regard 

 to C. Broivnii, which is classified by Dr. Kabenhorst as one of the 

 forms of C. cegngropila. On the other hand, Dr. Harvey states 

 that llobort Brown (who first described it as Conferva j^^^vinata), 

 Mr. Kalfs, and himself agreed in considering it a perfectly distinct 

 species, at least as well characterized as any other specific form in 

 the genus Cladophora, and better characterized than several reputed 

 speciesf. 



The fourth family, the (Edogoniacea', comprises three genera, 

 (Edogonmm, Cgmatonema, and Jitdbochcete. Much interest has at- 

 tached to the former genus, on account of Pringsheim's beautiful 

 observations upon the mode of im})regnation J in some of the 

 species. Many species remain, amounting in tliis work to upwards 

 of thirty, in Avhich the antheridia and oogonia are either imknown 

 or require further investigation, aff'ording a fine field for the atten- 

 tion of algologists. With regard to Cymatonema, the genus seems 

 quite unnecessary : and Dr. Ilabenhorst is apparently of this opinion; 

 for although it is figured in the ' Conspectus Generum,' the descrip- 

 tion in the text (p. 351) makes Cijmatonema a synonym of the 

 onginal name of the plant, (Edogoniimi undulatam, lireb. 0{ Bul- 

 hochfPte there are nine well-established species, besides seven others 

 unknown to the author or of doubtful validity. 



The fifth family, the Ulofrichccn, seems to require further con- 

 sideration. It contains the genera Harmlscia, Ulothri.r, Hormidiuni 

 (which is only the terrestrial form of Ulothri.v), and >ScJiizogonium. 

 Except for the occurrence of two kinds of zoospores (megazoospores 

 and microzoospores, as Areschoug § has called them), IJormiscia 

 might well have been placed in the Confervacea. Ulothrix has 

 hitherto been considered an ally of Drapnrnaldia, and >Siigeoch- 

 niuni and Schizogonium might with great propriety be placed in 

 the Ulvacem. It does not appear that the occurrence of two kinds 

 of zoospores (one of the main features of the family) has been noticed 

 in Uhthrix or in Schizogonium. 



The Chroolepidiece (fam. 6) comprise only two genera, Chroolejym 



* Micr. Diet. p. lo9. 



t ' Phycologia Britannica,' remarks under plate xxx. 

 I Jabrbiicher fiir wissimscliaftliche Botanik, vol. i. p. 1. 

 § Arescli. Obs. phvcol. in Act, Keg. Soc. ydent. Ups. ser. 3. vol. vi. 

 fasc. 1 (18G0). 



