152 Journal of the Mitchell Society [February 



when wet. The color of the plant in the fresh state a dull white, 

 which is a little darkened by the small openings of the cups and is 

 almost entirely due to the fine white powder covering the exposed 

 parts of the matrix as well as the outside of the cups. When very 

 young the plant is thin and sterile, with a minutely granular appear- 

 ance. The cups first appear as very small openings extending to 

 within 3^ mm. of the margin; later, when expansion ceases, they 

 are formed almost to the marginal line. 



Spores (of No. 4686) white, smooth, oval, 3.5-4.5 x 5-7.5[i. 

 Basidia clavate, 4-spored, Q.5]x thick. A most peculiar plant differ- 

 ing from other species of Solenia in the short, partly embedded cups. 

 We have compared our plants with several collections from America 

 and one from Bresadola at the New York Botanical Garden and find 

 them similar in all essentials. Most other collections have the cups 

 less crowded and in some they are broader. Our plant seems to be 

 a dense, small-cupped form Bourdot and Galzin give microscopic 

 characters which agree with ours, as spores 4-5 x 4.5-6.5[X; basidia 

 5-8 X 18-24^, 2-4 sterigmata; and Dr. Burt writes me that a col- 

 lection made by him in Sweden has spores 4.5-5 X 5-6^. Hennings, 

 in the Pflanzenfamilien, gives the spores as 3-3.5 x ll-14ix, which 

 is probably an error. 

 4275. On dead bark of old live grapevine (F. aestivalis), April 15, 1920. Spores 



pure white, short, oval. 

 4317. On bark of Vitis, May 28, 1920. 



4686. On dead bark of live, wild grapevines, November 13, 1920. 

 4700. On bark of live grapevine, December 4, 1920. Poorly developed specimens 



with few cups. 



ALEURODISCUS 



Plants in the species here treated growing on the bark of living 

 trees or dead shoots and forming entirely resupinate, white, small, 

 thin or thickish crusts with well-defined margins (the margin at times 

 is vague in A. botryosus) and hard, brittle flesh; or in one case form- 

 ing small cups with the margin free all around. Basidia and spores 

 large to very large; spores white, minutely punctate or spiny; no 

 cystidia or setae present, but paraphyses often of peculiar form occur 

 in the hymenium or throughout. 



Other groups of species included by Burt in this genus, but not 

 treated by us, have other characters separating them from the Ster- 

 eums. See Burt, Ann. Mo. Bot. Gard. 5: 177. 1918; Bourdot and 



