Seaver: The Hypocreales of North America 203 



sterile specimens which probably accounts for its having been 

 placed in the genus Hypocrea. A note from Kew made from 

 examination of Berkeley and Ravenel's specimen No. 1220 states 

 " no spores visible." Small cavities beneath the surface of the 

 stroma were evidently mistaken for the perithecia. This is the 

 number from which the description was drawn in Grevillea 

 4: 13. 



Other specimens examined from the Ravenel collection show 

 mature perithecia. The spore characters suggest Hypocrella or 

 Epichloe but the superficial position of the perithecia bar it from 

 either of those genera in both of which the perithecia are entirely 

 immersed or with the necks slightly protruding. 



21. Thyronectria Sacc. Grevillea 4: 21. 1875 

 Pleonectria Sacc. Nuov. Giorn. Bot. It. 8: 178. 1876. 



Stroma erumpent-superficial or subimmersed with the peri- 

 thecia in dense cespitose clusters ; individual perithecia subglobose, 

 smooth or rough or often clothed with a yellowish-green, fur- 

 furaceous coat which sometimes disappears with age leaving the 

 perithecia dark colored, red to brownish, collapsing or entire ; 

 asci 8-spored, cylindrical to clavate ; spores hyaline, when mature 

 many-septate and muriform, often accompanied by minute spore- 

 like bodies which are much smaller in size. 



Type species : Thyronectria Patavina Sacc. 



Distinguished by the muriform, hyaline spores. 



Spores elliptical, 2 times as long as broad. 



Perithecia subimmersed, greenish. 1. T. pyrrhoclilora. 



Perithecia erumpent-superficial, not green. 



Perithecia dark brownish ; spores small, 



10-15 X 7-9 mic. 2. T. denigrata. 



Perithecia reddish ; spores large, 16-30 mic. long. 

 Spores 20-30 X 10-12 mic, on bark of 



Carya. 3. T. missouriensis. 



Spores 16-20 X 7-8 mic, on Ribes. 4. T. berolinensis. 



Spores subelliptical, accompanied by minute spore-like 



bodies. 5. T. sphaerospora. 



i. Thyronectria pyrrhochlora (Auers.) Sacc. Michelia 

 1: 325. 1878 

 Nectria pyrrhochlora Auers. Hedwigia 8: 88. 1869. 

 Valsa Xanthoxyli Peck, Ann. Rep. N. Y. St. Mus. 31 : 49. 1879. 



