l6 ANCYLISTACEAE 



1. Zoospores escaping singly from the pore 



Leptomitus 7: 265, S. loi 



2. Zoospores remaining in a hollow ball about the pore before swimming 



Apodachlya S. 102 

 II. Branches different from the main stem 



1. Branches whorled Naegeliella S. 163 



2. Branches repeatedly umbellate-ramose Araeospora 14:454 



3. -Branches springing from the swollen tip of the main stem 



Rhipidium 7: 268, S. 103 



Subfamily Pythiae 



SCHROETER IO4 



Vegetative mycelium very narrow, uniform, much-branched ; sporangiophores not 

 distinct from mycelium ; zoosporangium filamentous, cylindric, ellipsoid or globose, 

 contents escaping in a globose vesicle in which the zoospores arise, zoospores 2-ciliate ; 

 oogones globose, terminal, rarely intercalary, l-spored. 



I. Zoosporangia filamentous Nematosporangium S. 104 



II. Zoosporangia globose or lemon-shaped Pythium 7: 270, S. 104 



Family 11. ANCYLISTACEAE 



ScHROETER Sp, 7:278, 9:348, 14:450, 16 : 395, 17:516 

 Mycelium mostly poorly developed and scarcely distinct from the fruit-body, the 

 latter tubular, when mature divided into vegetative cells, sporangia or oogones and 

 antherids ; entire contents of antherid passing into oogone, oospore lying free ; spo- 

 rangia always producing zoospores. 



Key to the Subfamilies 



I. Filament or fruit-body producing wholly sporangia or sex cells, mycelium entirely 



lacking Lagenidiae 



II. Filament producing vegetative cells also, the latter germinating to form threads 



Ancylistae 



Subfamily Lagenidiae 



Fruit-body filamentous, tubular, simple or branched, dividing into cells which 

 develop into sporangia or sex cells; antherids on the same or on different fruit bodies; 

 sporangia and oospores always giving rise to zoospores. 



I. In fresh-water algae, rarely in animals 



1. Filament simple 



a. Zoospores escaping singly from the sporangium 



Achlyogeton 7:277, S. 89 



b. Sporangial plasm poured out into a vesicle in which the zoospores are formed 



Myzocytium 7: 279, S. 90 



2. Filament with short side-branches Lagenidium 7: 278, S. 90 



II. In the root-hairs of plants Rhizomyxa 7: 278, S. 91 



Subfamily Ancylistae 



Fruit-body tubular, mycelium-like, unbranched or with few short side-branches, 

 when mature dividing into a number of chain-like cells, which develop into vegetative 



