EXPLANATION OF I'LATK XII. 



37. — Diclyniiuni proxiiiiuni, B. & C. a. Sporangium and slipe > 33. 

 b. Section through the columella. 



38. — Didyniiuni exiuiiuui, Peck. a. Showing the rough columella 

 of one form. b. Section through the discoid columella of the very 

 much depressed form. Magnified by 33. 



39. — Didymium minus, Lister, o. Sporangium and stipe > 33. 

 b. c. d. Sections through the columella showing differt-nt forms. 



40. — Didymium farinaceum, Schr. Section through the columella. 

 After Rostafinski. 



41. — Didymium anellus, Morgan, a. Growing upon a leaf X 3. b. 

 Plasmodiocarp X I7- 



42. — Spumaria alba, Bull. Var. i. didymium, sporangia ■ 3. Drawn 

 from a foreign specimen. 



43. — Spumaria alba, Bull. a. .4i;thalium natural size. b. Capillitium 

 and spores as seen by a magnifying power of 500 diameters. 



44. — Diderma flori forme, Bull. Slipe and columella X 20. 



45. - Diderma crustaceum, Peck. a. Sporangia crowded on the 

 thick hypothallus, natural size. b. Sporangia X 'i- '"■ Section through 

 outer coat, inner membrane, and columella. 



46. — Diderma cinereum, Morgan, a. Sporangia growing oti a leaf 

 X 3- b. Sporangia X 23. c. Section through the wall and columella. 



47. — Diderma reliculatum, Rost. Plasmodiocarp growing on 

 leaf X 3- 



48. — Diderma effusum, Schw. Plasmodiocarp effused on a leaf > 3. 



