Orthotricha. 109 



Echinostelium minutum, De Bary (fig. 202). 



Sporangia scattered, stipitate, globose, naked, whitish ; the 

 arcuate threads of the capillitium springing from the apex of 

 the stem, furnished with numerous acute, free branches ; spores 

 coloured, 6*7 8'3 p. diameter, smooth. 



Echinostdium .minutum, De Bary, in Host., Mon., p. 215, 

 figs. 53, 54, 58, and 68 ; Cke., Brit. Myx., figs. 53, 54, 58, 68 ; 

 Sacc., Syll., vii., 1, no. 1340. 



ORTHOTRICHA, Wingate. 



Sporangium globose ; stipe elongated, entering the sporangium 

 as a very short or obsolete columella, and then dividing into 

 a few branches at a sharp angle. These branches fork several 

 times, thus forming a capillitium of straight threads. The last 

 branches meet at the surface of sporangium at a very sharp 

 angle by twos or threes, where they are joined together by 

 small membranaceous plates. Wall of the sporangium, with 

 the exception of the plates and a very small collar around the 

 stipe, not apparent. 



Orthotricha, Wingate ; Proc. Acad. Nat. Sci. Phil., 1886, 

 p. 125; Sacc., Syll., vii., pt. I, p. 400. 



Distrib. United States. Sp. 1. 



Orthotricha microcephala, Wingate. 



Sporangia globose, very variable in size, from one-twelfth to 

 one-fourth of a mm. in diameter; stipe elongated, brown or 

 blackish at the base, growing lighter towards the top, more 

 or less translucent, ten to thirty times the diameter of the 

 sporangium in height, tapering, rugose, except at the upper 

 part, where it more or less suddenly becomes a smooth filament, 

 entering the sporangium as a very short, sometimes almost 

 obsolete columella. It then divides into a few (sometimes only 

 two) branches at a sharp angle. These branches fork several 

 times, forming a very loose capillitium of straight threads, the 



