Arcyria. 155 



Arcyria didyonema, Rost., Mon., p. 279, fig. 195; Cke., Myx. 

 Brit., fig. 195; Sacc, SylL, vii., 1, n. 14G9. 



Russia; Germany. 



Appears to approach very closely some forms of A. cmcrea 

 and A. nutans. 



(Rostafiuski's Synonyms.) 



Arcyria nutans, (a) sordide ochracea, Bong., in Wein., 1. c, 



p. 609 (1836). 

 Arcyria ochracea, D. By., MS. 

 Arcyria cinnaviomca, Kaulfuss, MS. 



Arcyria Hariotii, Mass. (n. sp.). 



Gregarious or much crowded and irregularly polygonal from 

 mutual pressure, depressed, sessile on a broad lase, sporangial wall 

 primrose-yrlloiv, smooth, shining, capillitium and mass of spores 

 dingy yellow ; threads of capillitium 6 — 8 ix diameter, forming 

 a dense, irregular net, uniformly and densely covered with mimUe 

 warts ; spores globose, wall thick, synooth, 7 — 9 fx diameter. 



France. Communicated by M. Hariot of the Pai-is Museum. 



On decayed wood. About "5 mm. diameter, superficially 

 closely resembling Oligoncma nitcns. Agrees in the smooth 

 spores, dense capillitium, and polished sporangium with Arcyria 

 versicolor, but in the latter the sporangium is clavate or elongato- 

 pyriform, and the markings of the capillitium consist of short 

 irregularly arranged bands. 



Arcyria aurantiaca, Raunk. 



Sporangia gregarious, ovate, or shortly cylindrical, stipitate ; 

 stem same length or shorter than sporangium. Thickenings 

 on the inner side of the receptacle, in the form of fine warts ; 

 wall, capillitium, and mass of spores brick-red to orange. Tubes 

 of the capillitium with irregularly connected, close-standing, 

 ring-like thickenings, 5 — 7 /x broad; spores smooth, 10 — 11 /x 

 diameter. 



