232 



ENDOSPOREAE 



[ARCYRIA 



Fig. 50. — Arcyria demidata Sheldon. 



a. Group of sporangia. Twice natural size. 



b. Capillitium. Magnified 250 times. 



c. Spore. Magnified 560 times. 



Fig. 50. 



B. Capillitium not elastic : — 



Sporangia sessile, heaped, ; sporangium- wall single, persis- 

 tent, papillose, not thickened with angular granules. 



(44) Lachnobolus. 



Fig. 51. — Lachnobolus congettus Lister. 



a. Cluster of sporangia. Twice natural size. 



b. Capillitium and spore. Magnified 300 times. 



Fie. 51. 



Sporangia sessile or stalked ; sporangium-wall usually 

 double, at least at the base, and the outer layer thickened 

 with dark angular granules. (45) Perichaena. 



Fig. 52. — Perichaena corticalis Rost. 



a. Group of sporangia. Magnified 7 times. 



6. Capillitium and spore. Magnified 280 times. 



Fig. 52. 



Genus 43.— ARCYRIA Wiggers Fl. Holsat,, 109 (1780). 

 Sporangia stalkedj (sometimes sessile in A. occidentalis) ; spor- 

 angium-wall evanescent above, persistent below as a mem- 

 branous cup ; stalk filled with spore-like cells ; capillitium 

 a more or less elastic network with thickenings in the form of 

 half-rings,* cog-like prominences or spines, or marked with a 

 broken reticulation, sometimes with three to five faint piraJ 

 lines in addition. 



This genus is allied to Hcmitrichia by those species in which the 

 capillitium is marked with faint spiral bands ; but the spirals never 

 constitute the most conspicuous markings of the threads as in 

 H emit rich ia. 



* The thickenings are in the form of minute rings in A. annulitcra. 



