146 University of California PuhUcations in Botany [Vol.8 



identity of the two plants. The specimens from the central Californian 

 coast, on the other hand, resemble more closely the Yendo plant in 

 habit but show no attaching fibrils. 



FAMILY 2. CHLOROCHYTRIACEAE nom. nov. 



Thallus unicellular, not united into colonies, or single unseptate 

 coenocytes, reproducing .solely by zoospores and by isoplanogametes. 



Planosporaceae West, Algae, vol. 1, 1916, p. 209. E ndosphaeraceae 

 Klebs, Organ, einig. Flagellaten-Gruppe, 1883, p. 344; Hansgirg, 

 Prodr. d. Algenfl. v. Bohmen, II, 1888, p. 124 ; Blackman and Tansley, 

 Rev. Class. Green Algae, 1902, p. 95. 



This is a small but fairly natural family including a number of 

 genera which are, however, mostly inhabitants of the fresh waters. 

 West (1916, p. 212) has reduced a number of genera under Chloro- 

 chytrium, as indicated elsewhere, among them being Endosphaera. 

 West has, consequently, set aside the family name Endosphaeraceae, 

 as adopted by Blackman and Tansley, and substituted the designation 

 "Planosporaceae." Since this does not embody one of the genera of 

 the family as reorganized it seems best to consider it inapplicable 

 under the present rules of nomenclature and to adopt "Chloro- 

 chytriaceae" as a fitting family name. 



As stated by West, "this family is established to include all those 

 non-coenobic members of the Protocaccales which are reproduced solely 

 by zoogonidia or isoplanogametes." The great majority of the mem- 

 bers of this family are either epiphytic or endophytic. 



Key to the Genera 



1. Cells sphericalto more or less ovoid 2. Chlorochytrium (p. 146) 



1. Cells cylindrico-oblong with a more or less elongated stipe 3. Codiolum (p. 151) 



2. Chlorochytrium Cohn 



Thallus unicellular, rounded, with ehromatophore covering more 

 or less of the outer wall and continuous or with radial prolongations, 

 containing one to several pyrenoids; asexual reproduction by akinetes 

 or by 2- or 4-ciliated zoospores escaping singly or enclosed in a gela- 

 tinous mass ; sexual reproduction b}^ 2-ciliated isogametes escaping in 

 a gelatinous utricle mass and conjugating before separation, or escap- 

 ing singly and conjugating in the water; zygote, 4-ciliated, at first 

 motile, later coming to rest and penetrating the host plant. 



Cohn, Ueber parasitische Algen, 1872, p. 102, diagnosis. 



