EXPLANATION OF PLATE XL (continued). 



Fig. 



ARCyRL\ CINEREA, Fries. — A single sporangium, completely filled with half- 

 matured spores, X 25. 



23. Phlebomorpha rufa, de Bary.— Portion of horny rcte or capillitium, with 



enclosed spores, x 390. 



24. DiDYMIUM SERPULA, Fries.— Section of sporangium, showing contained 



spores. 



25-28. Lvcogala epidendron, Fries.— 25, Two isolated spores ; the one at a bursting 

 and liberating its monadiform germ, x 390 ; 26, three fully developed, free- 

 swimming, highly polymorphic monadiform zooids, developed from the 

 spores represented in the preceding figure, x 390; 27, amceboid condition 

 assumed by the same monadiform zooids, representing the first step towards 

 the development of the compound plasmodium ; 28, Young repent amcebi- 

 form Plasmodium formed by the coalescence of several of the smaller 

 amoeboid particles. 

 29. .^THALIUM septicum, Fries. —Young repent plasmodium, x 200. 



30, 31. DiDVMlUM FARINACEUM, Fries. — 30, Fragment of peridium or indurated outer 

 wall of sporangium, containing substellate calcareous spicula, x 390; 31,, an 

 isolated spicule from the same peridium further enlarged. 



32-35. DiDYMIUM SERPULA, Fries. — 32-34, Polymorphic monadiform zooids, the 

 example at 32 with ingested food-particles ; «, nucleus or endoplast ; c v, con- 

 tractile vesicle, X 350; 35, amcebiform condition of a similar monadiform 

 zooid, X 350. 



36-38. Trichia varia, Pers.— 36, Isolated spore, x 390 ; 37 and 38, the same spore 

 with its wall ruptured, and giving exit to a free-swimming monadiform 

 zooid. 

 39. DiDYMIUM Libertianum, Fries. — Minute subaqueously developed sporangium, 

 with nine or ten contained spores, x 390. 



40-44. Stemonitis OBTUSAta, Fries. — Successive phases of multiphcation by fission 

 of a monadiform zooid, X 390. 



45-47. DiDYMIUM LEUCOPUS, Fries. — Young repent amcebiform plasmodia, containing 

 {c V, V c) numerous contractile vesicles, the plasmodia at 45 and 46 being 

 in a contracted, and at 47 in a fully extended state, x 350. 



