arcyria] trichiaceae 233 



KEY TO THE GENERA OF ARCYRIA. 



A. Spores 9 to 11 yu. diam. ; sporangia orange-red or buff : — 

 Sporangia ovoid ; wall reticulated. 1. A. ferruginea 

 Sporangia clavate ; wall papillose. 2. A. versicolor 



B. Spores 6 to 8 /x diam. : — 



a. Cup entire— 



a. Capillitium attached to the cup — 



Sporangia clavate, grey or yellowish ; capillitium 

 closely spinulose or warted. 3. A. cinerea 



Sporangia globose, yellow ; capillitium with spines 

 arranged in an open spiral. 4. A. pomiformis 



Sporangia globose, whitish, on slender stalks ; capilli- 

 tium closely spinulose or warted, the warts usually 

 arranged in more or less spiral lines. 5. A. globosa 



Sporangia globose, ochraceous ; capillitium very 

 slender, marked with complete rings. 



6. A. annulifera 



Sporangia red, ovoid or subcylindrical ; capillitium 

 marked with cogs and half-rings. 7. A. denudata 



Sporangia rose-coloured, cylindrical or ovoid, small ; 

 capillitium threads slender, marked with transverse 

 bands and minute spines. 8. A. insignis 



Sporangia glaucous ; capillitium marked with trans- 

 verse bands and spines. . 9. A. glauca 



b. Capillitium almost or quite free from the cup— 



a. Network of mature capillitium expanding, not droop- 

 ing— 



Capillitium marked with cogs and spines only. 



10. A. incarnata 

 Capillitium marked with cogs, spines, and three to 

 four indistinct spiral bands in addition. 



11. A. stipata 

 ft. Network of mature capillitium becoming much 



elongated, drooping — 



Sporangia buff ; wall evanescent above. 



12. A. nutans 

 Sporangia red ; wall persistent above in a few shield- 

 like fragments. 13. A. Oerstedtii 



b. Cup at length dividing nearly to the base in rounded 



lobes. 14. A. occidental is 



