220 



[Vol. 7 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



54645); Tepeite Valley, Guernavaca, W. A. & E. L. 

 Murrill, 4O8, comm. by N. Y. Bot. Gard. Herb, (in Mo. 

 Bot. Gard. Herb., 54544); Xuchiles, Cordoba, W. A. & 

 E. L. Murrill, 1209, 1210, comm. by N. Y. Bot. Gard. Herb, 

 (in Mo. Bot. Gard. Herb., 54598, 54599). 



72. S. heterosporum Burt, n, sp. Plate 6, fig. 72. 



Type: in Mo. Bot. Gard. Herb. 



Fructifications coriaceous, thin, resupinate, orbicular, becom- 

 ing confluent, sometimes reflexed, with the upper surface villose, 

 bister, somewhat concentrically sulcate and zonate, the margin 

 entire, whitish ; hymenium even, somewhat velvety, bister, becom- 

 ing light drab and somewhat pruinose in the center with age; in 

 structure 300-500 n thick, the intermediate layer with a darker 

 zone on its upper side and composed of loosely and longitudinally 

 arranged, slightly colored hyphae 3-3| ix in diameter, many of 



Fig. 43. S. heterosporum. Section X 90; hyaline cystidium, c, colored cystidium, 

 c', hyaline spores, s, colored spores s', X 665. 



which curve into the hymenium and often become there as dark- 

 colored as conducting organs and sometimes incrusted; hyme- 

 nium 70-120 yu thick, becoming more or less zonate, with cystidia 

 incrusted starting from all parts of the layer, 30-35X6-7 ii, 

 protruding up to 15 ii, often colored under the incrustation in 

 the deeper layers of the hymenium; paraphyses filiform, 2 /^ 

 in diameter, branched, numerous at the surface of the hymenium; 

 basidiospores hyaline, even, 8-9 X3| ij., borne 4 to a basidium; 

 ochraceous spores of the same form and dimensions as the 

 basidiospores often occur copiously imbedded throughout the 

 hymenium. 



