ARCYRfA 191 



threads are remarkable for their graceful slenderness, regu- 

 larity, and symmetry. 

 Pennsylvania. 



2. ARCYRIA GERSTEDTII Rost. 



1875. Arcyria cerstedtii Rost., Man., p. 278, Fig. 196. 



Sporangia cylindric, arcuate, 1.5 mm. high when unexpanded, 

 closely clustered, dull crimson, stipitate ; peridium evanescent, 

 except here and there a persistent patch, the calyculus shallow, 

 plicate, papillose within ; stipe short, weak, concolorous ; hypo- 

 thallus distinct, membranous, concolorous ; capillitium a loose, 

 far-expanding, elastic net, the meshes uneven, often small, the 

 threads characterized by much irregularity and many bulbose 

 thickenings, especially at the nodes, strongly spinulose through- 

 out ; spore-mass crimson or reddish brown, dull ; spores by 

 transmitted light colorless, nearly smooth, sub-globose, 9-10 /*. 



This well-marked species is certainly rare within our limits. 

 We have specimens from New England and from Pennsylvania. 

 The Iowa material referred to this species, Bull. Lab. Nat. Hist, 

 la., II., p. 125, is A. magua Rex. Rostafinski's figure is excel- 

 lent in the present case, and gives the idea of what we regard 

 the typical marking of the capillitium in A. cerstedtii. Exter- 

 nally the species resembles somewhat A. uodulosa, and the 

 network of the capillitium is also suggestive of that form ; the 

 spiny capillitium is unique. 



Rare. Adirondacks, New York Dr. Rex. 



3. ARCYRIA NUTANS (Bull.} Grev. 



PLATE II., Figs. 6, 6 a, 6 b. 



1791. Trichia nutans Bulliard, Champ., p. 122, t. 502, ill. 

 1794. Arcyria flava Pers., Romer N. Mag. Bot., I., p. 90. 

 1824. Arcyria nutans Grev., Fl. Edin., p. 455. 



Sporangia crowded, cylindric, about 2 mm. high when unex- 

 panded, pale yellow or buff, short-stipitate or sessile by an acute 

 base ; peridium wholly evanescent, except at the base, where 

 persists the shallow, colorless, often inwardly spinulose, plicatu- 



