CLASTODERMA.] STEMONITACE^. 133 



the ultimate branches attached singly or two or three together 

 to the membranous plates of the sporangium -wall. Spores pale 

 lilac, smooth, 7 to 10 /x, diam. Christ. Vidensk. Forh., No. 4(1882); 

 Bidr. K. Norg., Sop. iii. (1892), p. 7. Orthotrichia microcepliala 

 Wing., I.e. ; Mass., Mon., p. 109. 



Plate L., B. a. sporangia, x 20 ; TJ. apex of stem, capillitium, and 

 spores, x 280 ; c . part of capillitium from another sporangium, x 280 

 (United States) ; d. capillitinm with expanded membranous plates, x 280 

 (Norway) ; e. spore, x 600 ; /. sporangium, x 20 (Norway). 



This species was discovered by Prof. Blytt in 1879, near Christiania, 

 growing on dead Pohfporus. In the United States it has been re- 

 peatedly found, and described by Mr. Wingate as Orthotrichia micro- 

 cephala. In these gatherings the threads anastomose more freely than 

 in the Norwegian specimen, and the disc-shaped fragments of the 

 sporangium-wall are usually less pronounced. In some sporangia, 

 however, they agree essentially with the type kindly submitted for 

 examination by Prof. Blytt, and it cannot be doubted that they are 

 the same species. 



Hal}. On dead wood. Norway (Christiania Herb.) ; Borneo 

 (L:B.M.100) ; Philadelphia (B. M. 874) ; Ohio (LrB.M.lOO). 



ALLIED GENERA NOT MET WITH IN THE QUOTED COLLECTIONS. 



RACIBORSKIA Bcrl., in Sacc. Syll., vii., p. 400 (1888). Spor- 

 angia naked, globose, stipitate. Stem produced into a columella 

 one-third or half the height of the sporangium, bearing at its apex 

 short, slender, secondary columellae, which branch again in a 

 similar manner, the ultimate branches combining to form a net- 

 work without free ends. Rostajmskia Racib., in Rozpr. Mat. 

 Przyr. Akad. Krak., xii., p. 77 (1884). 



1. R. elegans Berl., I.e. Sporangia naked, globose, 0*5 mm. 

 broad. Stalks erect, 1 to 2 mm. high, subulate, furrowed, black. 

 Columella cylindrical, 8 to 10 /JL wide. Capillitium blackish- 

 violet, the branches becoming gradually more slender outwards, 

 the ultimate branchlets furnished with scattered spines. Spores 

 dull violet, 9 to 10 /x diam. Eostafaiskia elegans Racib., I.e., p. 78. 



Hal). Botanical Gardens, Cracow. 



This description applies to Comatrlclia obtusata, in which the 

 columella frequently branches in a dichotomous manner. 



ECHINOSTELIUM de Bary, in Rost., Yersuch, p. 7 (1873). 

 Sporangia stalked, minute, naked, without columella. Capillitium 

 arising from the apex of the stalk, its branches forming a 

 network. 



1. E. minutum de Bary, in Rost., Mon., p. 215, figs. 53, 54, 

 58, 68. Sporangia scattered, stipitate, globose, 37 to 57 ^ diam., 

 naked, whitish. Stalk 0'28 to 0'46 mm. high, brownish below, 

 pale above. Capillitium of curved branching threads, with acute 

 free branches. Spores entirely colourless, 6'7 to 8'3 /x, diam. 



Hab. Frankfort-on-Maine. 



