656 



can not perhaps now be certainly decided. It agrees tolerably with 

 Tode's figure, but it is not that species as understood by Nitschke, and 

 described by him (under Hypoxylon semiimmersum) as having spo- 

 ridia 16-20x 8-10 /i, and by Fckl. (under the name of II udum) as 

 having sporidia 28 x 10 p.. We have therefore accepted H. Ravenelii, 

 Rehm, as a distinct species. 



H.? atrofiiscum, B. & C. 



Fuckelia atrofusca, B. &C. Grev. XII, p. 51. 



Pustules erumpent, very small (hardly J mm. diam.), elliptical, 

 margined by the ruptured bark. Perithecia unequally distributed in 

 the black, depressed stroma. Asci cylindrical, stipitate. Sporidia 

 elliptical, brown, 13x7 ju. 



On bark of Rhus glabra, mountains of Virginia. 



H. hydnicolum, (Schw.) 



Sphczria hydnicola, Schw. Syn. N. Am, 1207. 

 Hypoxylon hydnicolum, Cke. Syn. 1034. 



Stroma thick, short, subrepand, here and there confluent; extern- 

 ally very black, granulose. Perithecia large, subdistant, immersed in 

 the light yellow substance of the stroma, monostichous, furnished with 

 a brown veil or sack. Ostiola prominent, papilliform. The teeth of 

 the Hydnum are often concrescent with the stroma, which then 

 appears stipitate. Substance of the stroma distinctly suberose. The 

 diameter of the stroma scarcely exceeds 4-6 mm. 



Rather rare; on the teeth of decaying Hydnums, Bethlehem, Pa. 

 (Schw.). 



From an examination of the specc. in Herb. Schw. we add the 

 following notes: Stroma subtubercular, 2-4 mm. across. Perithecia 

 only slightly prominent. Ostiola papilliform. Asci 75-80 jut long, 

 p. sp. 60 x 6 fi, cylindrical. Sporidia uniseriate, elliptical, pale brown, 

 with a single large nucleus, 10-11 x 4 /i. 



H. exaratum, (Schw.) 



Sphceria exarata, Schw. Syn. N. Am. 1206. 

 Hypoxylon exaratum, Cke. Syn. 1032. 



Effigurately eifused, surface marked with parallel, longitudinal 

 furrows, at first covered by the epidermis which is persistent in the 

 furrows. Perithecia very prominent on the ridges, irregular, black- 

 brown, with a black papillate ostiolum, rather large, monostichous, 

 surrounded with a scanty stroma, which has a sterile, subrepand 

 margin, and rests on a crust formed of the blackened substance of the 

 bark. 



