EXPLANATION OF PLATE XXI 



Echinoslelium minutum de Bary 



Figs. 552, 553. Habit, X 130; detail of sporangium without the peridium, X 550. 



Clastoderma debaryanum Blytt 

 Fig. 554. Habit, X 65. 



Klristobohts pitsillns Lipp. 



Figs. 555, 556, 557, 558. Section, X 550; detail of operculum, X 550; detail of outer 

 edge of the operculum, X 1200; spores, X 1200. 



Physarum vernum Somm. 



Fig. 559. Spore, X 1200. 



Physarum confertum Macbr. 

 Fig. 560. Spore, X 1200. 



Hemitrichia minor G. List. 



Figs. 561, 565. Vesicular thickenings of the capillitium in a culture collection, X 550; 

 a globose sporangium with circumscissile dehiscence, from culture, X 20. 



Dianema corticatum List. 



Fig. 562. Clump of typical spores, X 1200. 



Schenclla simplex Macbr. 



Figs. 563, 564. Section showing the capillitial columns which support the peridium, 

 X 15; after Macbride; a single column with component threads, X 30; after 

 Macbride. 



Didcrma chondriodcrma (de B. & R.) G. List. 



Figs. 566, 567, 568, 569. Habit, X 10; dark capillitial thread, X 550; pale capil 

 litium and spore, X 550; spore, X 1200. 



Cratcrium aitreum (Schum.) Rost. 



Figs. 570, 571. Habit to show internal character, X 10; capillitium, X 550. 



Alwisia bombarda Berk. & Br. 

 Fig. 572. Habit, X 12. 



Physarina echinoccphala von Hohnel 



Fig. 573. Section of a sporangium, X 30. After von Hohnel. 



