586 



each other, and confluent below, conical from an elliptical (seldom 

 orbicular) base, seated on the inner bark, 3-6 nun. long, 1-2 mm. high, 

 the elliptical disk erumpent, enclosed on each side by the transversely- 

 ruptured epidermis, whitish inside. Perithecia 6-30 in a stroma, in 

 one or two layers, ovate or angular from ci-owding, with necks more 

 or less elongated, and rather large, rounded, faintly 4-6-sulcate, black, 

 slightly prominent ostiola. Asci oblong-clavate, long-stipitate, p. sp. 

 70-100 X 9-12 n, paraphysate, polysporous. . Sporidia irregularly 

 crowded, allantoid, yellowish, 6-8 x 1 J //. 



On dead birch limbs, Bethlehem, Pa. (Ell. & Hark.). 



D. betiilina, Pk. 25th Rep. p. 101, PI. I, figs. 27-31. 



Exsicc. Ell. & Evrht. N. A. F. zd Ser. 2347. 



Stroma transversely erumpent, prominent, elliptical, black outside, 

 green within, 1J-2J mm. diam., loosely surrounded by the ruptured 

 epidermis, penetrating to the wood, on which, it forms a white spot 

 surrounded by a black line, nearly plane above and dotted by the 

 numerous, slightly prominent, stellate ostiola. Perithecia crowded in 

 a single layer, elliptical, black. Asci polysporous, stipitate, clavate- 

 fusoid, 100-110 (p. sp. 50-60) x 6-7 fi, paraphysate. Sporidia crowd- 

 ed, allantoid, yellowish, slightly curved, 4J-5|xl jj.. 



On bark of dead birches, northern U. S. and Canada. 



^ D. decorkta, Nitsclike, Pyr. Germ. p. 79. 



Microstoma vulgare, Awd. in Fckl. F. Rh; 1035. 



Stromata small, tuberculifbrm-hemispherical, 2-2| mm. broad at 

 base, embraced laterally by the lobes of the ruptured epidermis, the 

 brownish-black apex slightly arched. Perithecia 6-12 in a stroma, 

 monostichous, (jrowded, globose or ovate, abruptly contracted above 

 into slender, short necks with their stellate-cleft, black ostiola barely 

 erumpent. Asci (p. sp.) 40-48 x 5 /i, with a long, slender stipe and 

 slender, filiform .paraphyses. Sporidia crowded, cylindrical, slightly 

 curved or straight, brownish, 5-6 x 1 fi. 



On dead limbs of birch, London, Canada (Dearness). 



D. Missouri6nsis, E. & E. (in Herb.) 



Stromata scattered, wart-like or tubercular-hemispherical, 1| mm, 

 diam., and about 1 mm. high, seated on the inner bark, with a dark 

 circumscribing line penetrating to the wood, erumpent and closely 

 surrounded, except the drab-gray disk (which becomes black), by the 

 lobes of the substellate-ruptured epidermis. Perithecia 8-12 in a 



