1926] 



BURT — THELEPHORACEAE OF NORTH AMERICA. XV 337 



slightly colored gloeocystidia. The latter locate this species in 

 the subgenus Bourdotia of Sebacina. 



Specimens examined : 

 Grenada: Grant Etang, R. Thaxter, comm. by W. G. Farlow, 153, 



t>T)e (in Mo. Bot. Gard. Herb., 55236). 



S. plumbescens Burt, Mo. Bot. Gard. Ann. 3: 241. 1916. 



S. plumbea Burt, Mo. Bot. Gard. Ann. 2: 765. textf. 6, pi. 27, 

 f. 20. 1915, but not of Bresadola & Torrend, Broteria 11: 87. 

 i. 8. 1913.— >S. Burti Trotter in Sacc. Syll. Fung. 23 : 573. 1925. 



S. murina Burt, n. sp. 



Type: in Mo. Bot. Gard. Herb. 



Fructifications effused, closely adnate, very thin, pallid mouse- 

 gray and somewhat pulverulent when dry, even, the margin 

 similar; in section 30 [x thick, not colored, composed chiefly of 

 longitudinally septate basidia starting almost directly from the 

 substratum, 15 X 8 (x, and of immersed, white, incrusted masses 

 up to 25 X 7 [JL as seen in lactic acid preparations, densely covered 

 with spiculose granules which clothe a short, cylindric, flexuous, 

 hyphal axis for each mass; spores simple, hyaline, even, 9x6 [x. 



Fructifications 5-6 cm. long, 13^-2 cm. wide. 



On decorticated, weathered, badly decayed wood on mountain 

 side at altitude 800-1500 feet. Mexico. January. 



S. murina is noteworthy by the small, erect, cylindric, incrusted, 

 white masses between its basidia. These masses are evidently 

 homologous with the paraphyses of S. calcea but differ from the 

 latter by being unbranched, as shown when their spiculose, in- 

 crusting matter is cleared away by potassium hydrate solution; 

 the central axis of each mass then becomes visible as a cylindric, 

 flexuous rod somewhat olivaceous in color in preparations stained 

 with eosin and very similar in appearance then to the organs 

 termed gloeocystidia by Bourdot & Galzin in the subgenus 

 Bourdotia of Sebacina. 



Specimens examined: 

 Mexico: Motzorongo, near Cordoba, W. A. & E.L. Murrill, 986, 



type, comm. by N. Y. Bot. Gard. Herb, (in Mo. Bot. Gard. 



Herb., 54609). 



