639 



H. pruinktnin, (Klotszch). 



Sphisria pr-uinaia, Kl. in I^innsea, 1883, p. 489. 

 Rosellinia pruinata, Sacc. Syll. I, p. 259. 

 Hypoxylon Holwayii, HU. in Am. Nat. Feb. 1883, p. 193. 

 Hypoxylon pruinatum, Cke. Syn. 925. 

 Exsicc. Ell. N. A, F. 1182. 



Stroma J-| cm. diam., i-ather thin, orbicular, black within, sur- 

 face covered with a white-pruinose coat, except the projecting, acutely 

 papillose, black ostiola. Perithecia in a single layer, 20-30 in each 

 stroma. Asci cylindrical. Sporidia uniseriate, oblong, brown, 1-2- 

 nucleate, 22-27 x 11 ji, resembling the sporules of a Sphmropsis. 



On, the bark of trees. North America (Dr. Richardson), on the 

 bark of dead poplars, Iowa (Holway). 



In the Iowa specc, surrounding the stroma and standing out 

 obliquely like a coarse fringe, are short, coarse, black, bristle-like 

 teeth, like the teeth of a Hydnum or Irpex. This curious growth 

 also arises from the surface of the inner bark for some distance around 

 the stroma, soon throwing off the epidermis and leaving the blackened 

 surface of the inner bark exposed. This growth is analogous to that 

 of Institale acariforme, Fr., in connection with ^y/joasj/Zo/i coccin- 

 eum. 



We have not seen the original specc. of IT. pruinatum, KL, but 

 as the peculiarity just mentioned seems to he the only character sepa- 

 rating H. Holwayii from that species, we have placed the latter as a 

 synonym, as has been done by Cooke in his synopsis, No. 925. The 

 conidiiferous growth around the stroma may be only accidental, as it 

 was not found in all the specimens. 



** Stroma externally black. 



H. leucocreas, B. & Rav. Grev. IV, p. 51. 



"Small, about ^ a line across, black, papillate from the projection 

 of the perithecia. Stroma snow-white. Asci linear. Sporidia in a 

 single row, minute, elliptical, brown." Sporidia (sec. Cke. in Grev.) 

 5 X 2i fi. 



On limbs of oak. South Carolina (Ravenel). 



H. exignum, Cke. Grev. XI, p. 130. 



"Pulvinate, convex-applanaje, black, oval or discoid (2-3 mm. 

 broad), here and there confluent. Perithecia minute, numerous, papil- 

 late. Asci cylindrical. Sporidia very minute, elliptical, dark, 3| x 2 /i. 

 A most distinct species, easily recognized by the exceedingly minute 

 sporidia, which are a little larger in the American specimens." 



On rotten wood, Alabama and Carolina, also in Mauritius. 



