CLINTON: NORTH AMERICAN USTILAGINEAE. 
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age sometimes become powdery. The specimens on Carex Sitch- 
ensis , sent by C. H. Thompson from California are unusual in that 
many of the sori are elongated, varying from subspherical to three or 
four times as long as broad. Cocconi and Brefeld have described 
the germination. Literature : 23, 34, 115. 
Cintractia externa (Griff.) Clint. 
Tilletia externa Griff., Bull. Torr. Bot. Club, 29 : 290. 1902. 
Cintractia externa Clint., Journ. Myc., 8 : 142. 1902. 
Exsiccati : Cintractia externa (Griff.) Clint., on Carex jilifolia , Seym. & 
Earle, Econ. Fungi Clinton Ust. Supp., C 2; Tilletia externa Griff., on 
Carex filifolia, Griff., West Amer. Fungi, 305. 
Sori in the ovaries, subspherical, about 3 or 4 mm. in diameter, 
forming a firmly agglutinated black spore mass that on absorbing 
moisture becomes smeared over adjacent parts, with evident small 
columella; spores black brown, opaque, ovoid to spherical, smooth, 
provided with hyaline membranes of which the thin inner forms 
part of cell wall and the outer the evident remains of the fertile 
hyphae, 17-22 /x in diameter. 
Host: Carex filifolia , Mont, (collected by F. W. Anderson, Apr., 
1888, at Sand Coulee), Neb. (collected by T. A. Williams, June 23, 
1890, at War Bonnet Canon), Wyo. (type). 
This species was first collected fifteen years ago by Anderson, 
who distributed it to several herbaria under the name TJstilago 
Caricis. Later it was collected, by Williams. Recently it has been 
described from Wyoming as a species of Tilletia by Griffiths. It 
is closely related to Cintractia Caricis , which also occurs on the 
same host species, but differs in having more regular, smooth spores 
with evident hyaline enveloping membranes. These membranes are 
evidently hygroscopic and by means of the absorbed water the spores 
are shed. The germination is not known. Literature : 29, 72. 
Cintractia Luzulae (Sacc.) Clint. 
Ustilago Luzulae Sacc., Myc. Ven. Spec., 73. 1873. 
Cintractia Luzulae Clint., Journ. Myc., 8 : 143. 1902. 
Sori in the ovaries or occasionally extending to the base of the 
dowers, subspherical, about 2 mm. in diameter, usually concealed by 
