CHYTRIDIALES 559 



KARLINGIOMYCES, gen. nov. 1 

 (Fig. 32 C, p. 554) 



Thallus predominantly monocentric, eucarpic, consisting of a repro- 

 ductive rudiment usually formed from the body of the encysted zoo- 

 spore and several to many branched rhizoidal axes; sporangium usually 

 with more than one discharge papilla each surmounted by an operculum, 

 and in some instances, with an endooperculum as well; zoospores 

 formed within the sporangium, posteriorly uniflagellate, with one or 

 more globules, at discharge forming a compact motionless group and 

 sometimes undergoing a period of collective swarming before dispersing; 

 resting spore asexually formed, thick-walled, borne like the sporangium 

 on the thallus, upon germination functioning as a prosporangium. 



Saprophytes on vegetable debris and chitinous substrata. 



The genus as established here includes those species of Karlingia 

 Johanson with exoopercula (cf. R/n'zophlyctis, p. 435). The type species 

 of her genus is here retained in Rliizophlyctis. 



The genus is named for J. S. Karling, well-known student of chy- 

 tridiaceous fungi. 



KEY TO THE SPECIES OF KARLINGIOMYCES 



Zoospore with a single globule 



Resting spores abundantly formed; fungus strongly chitinophilic 

 Resting spore wall bearing straight or curved spines; rhizoids not 

 constricted 



Spines straight, blunt, peglike K. asterocystis, p. 560 



Spines curved, hooklike, very numerous. ... K. curvispinosus, p. 560 

 Resting-spore wall smooth to rugose or verrucose; rhizoids ir- 

 regularly constricted, thick-walled K. dubius, p. 561 



Resting spores lacking; fungus cellulosic K. marilandicus, p. 562 



1 Karlingiomyces, gen. nov. - - Thallus praecipue monocentricus, eucarpicus, ex 

 rudimento reproductive oriens. eodem ab zoospora cystoidea et axibus pluribus 

 ramosis derivato. Sporangium plerumque pluribus papillis emittientibus operculatis 

 praeditum; etiamque interdum endooperculatum. Zoosporae postice uniflagellatae, 

 noviciae in massa compacta immobiles post demum gregatim natantes vel cito 

 dispersae. Spora perdurans in thallo asexualiter originata, crasse circumvallata, 

 germinatione prosporangium simulans. 



Saprophyticus in substratis chitinosis vel putrescentibus partibus vegetabilium. 



Species typica: Karlingiomyces asterocystis, primum descripta ex "Charles 

 County, Maryland" in Mycologia, 41: 509, figs. 9-19, 1949. 



