150 Natural, History Bulletin. 



key to the genera. 



A. Sporangia distinct or plasmodiocarpous. 



a. Capillitium in part with strongly thickened spiniform branches. 



* All the capillitial threads uniformly thickened and colored; the 



branches spine-like, Cienkowskia. 



•* * Capillitium as if of two sorts, delicate, with occasional calcareous 

 thickenings, and stout, consisting of calcareously thickened spine- 

 shaped tubes, Physarella. 



b. Capillitium uniform throughout. 



* Capillitium generally thin, thread-like, widened here and there into 



vesicles which are charged with lime-granules. 



1. Capillitial threads arising from a somewhat broad base, 



dichotomously branching, anastomosing, becoming thin 

 at the free ends, Tilmadoche. 



2. Capillitial threads irregularly branched, netted, adherent 



to the peridial wall. 



a. Peridium double; capillitium knots only in part 



calcareous, IvEocarpus. 



b. Capillitium knots generally calcareous. 



■j- Peridium opening by a lid, . Craterium. 



t t Peridium opening variously, . Physarum. 



* * Capillitium calcareous throughout, Badhamia. 



B. Sporangia combined to form large cushion-like sethalia, . . . Fuligo. 



CIENKOWSKIA, Rostafinski. 



Sporangia plasmodiocarpous. Peridia simple, opening irreg- 

 ularly. Capillitium widi some of the branches free, these 

 apiculate. Calcareous granules well developed, frequently- 

 branched. 



50. Cienkowskia reticulata, Albertini and Schweinitz. 

 Plate IX, Figs. 6, 6a and 6h. 



Sporangia plasmodiocarpous, creeping, reticulately inter- 

 woven, orange or brown. Capillitium with calcareous gran- 

 ules. Spores violet-tinted, smooth, shining, .009 in diameter. 



Rare. Found in undisturbed woodland, in scanty colonies 

 on dead leaves. Our specimens are clear orange -yellow 

 under low magnifying power, somewhat rough. The capil- 



