SAPROLEGNIA LES 



161 



function at times as in Achlya. A third species referred to the 

 genus as T. achhjoides Coker & Couch (1923: 112) has since 



I- no 



Fig. 57. — Thraustothcca clavata (de Bary) Humphrey, {a-c) An unusually 

 small sporangium, showing delimitation and escape of sporangiospores. (d-f) 

 Liberation of swarmspore from sporangiospore. {g, s) Germination of cysto- 

 spore (encysted swarmspore) by germ tube, {h) Cystospore forming dwarf 

 sporangium, (n) Two-spored dwarf sporangium, (p) Oogonium accompanied 

 by antheridial branch. {After Weston 1918.) 



been made the basis of the genus Calyptraleg7iia Coker (1927: 

 219); while a fourth species, T. unisperma Coker & Braxton 



