CHYTRIDIALES 561 



(10-80 by 15-140 \x), pyriform (8-70 by 18-160 u.), obclavate, oblong, 

 or elongate, with one to three low and inconspicuous or cone- or dome- 

 shaped and prominent exit papillae; rhizoids for the most part emerging 

 from several places on the sporangium, main axes coarse and up to 1 6 u, 

 in diameter, much branched and extensive; operculum surmounting the 

 discharge papilla, quickly disappearing after dehiscence, 6-18 \i in 

 diameter; zoospores hyaline, spherical, 3.8-4.2 jjl, with a hyaline refrac- 

 tive globule, 0.6-0.8 \i in diameter, and a fiagellum 10-13 [i long, not 

 swarming in a vesicle after discharge; resting spore spherical (6-21 y. in 

 diameter), oval (8-12 ji. by ll-16u,), or slightly angular and irregular, 

 covered with numerous curved, somewhat hooked-shaped pegs or 

 spines, occasionally verrucose, rarely echinulate or smooth, dark amber 

 or brown, contents evenly granular with a small central vacuole, at 

 germination functioning as a prosporangium. 



Saprophytic on chitinous substrata in soil and water, United States. 



This species resembles Karlingiomyces asterocystis in the type of 

 resting spores, but differs from it in having spores with more numerous, 

 curved or hooked, spines on them. It also has smaller zoospores with 

 a shorter fiagellum which do not swarm in a vesicle. Karling 

 points out that in K. curvispinosus the developing spiny resting spores 

 are surrounded by a relatively clear zone of material as they are in spe- 

 cies of Rozella and Olpidiopsis. 



Karlingiomyces dubius (Karling), comb. nov. l 



(Fig. 32 C, p. 554) 



Karlingia dubia Karling, Mycologia, 41: 513, figs. 36-51. 1949. 



Sporangium smooth-walled, hyaline, subspherical (20-240 \j. in diam- 

 eter), oval (45-65 by 60-75 ;x), pyriform (15-35 by 40-78 ;x), or oblong, 

 with one to four exit papillae, 12-34 jx in diameter, below which is a 

 hemispherical area up to 12 (x in diameter that may extend to a depth 

 of 16 jx into sporangium; rhizoids for the most part emerging from 

 several places on the sporangium, main axes attaining a diameter of 

 16 [x, much branched and extensive, usually thick-walled with many 

 regular or irregular constrictions which may extend almost completely 



i See also Willoughby (1957). 



