414 



ridia ovoid-oblong, continuous, subhyaline. The genus has the habit 

 of Phyllachora or Rhytisma. 



T. quercina, (Fr. & Rud.) (Plate 31) 



Rhytisma quercinum , Fr. & Rud. in L,inn. Trans. 1830, p. 551. 

 Asteroma parmelioides, Desm. Pi. Crypt. Ed. I, 1737. 

 Rhytisma riccioides, Letellier Champ. V, tab. 629, fig. 4. 

 Sphceropsis riccioides, Lev. Ann. Sci. Nat. III. Ser. torn. p. 257. 

 Trabutia quercina, Sacc. & Roum. 1. c. 

 Fxsicc. Thum. M. U. 2271. KI1. N. A, F. 1288. 



Perithecia hemispherical, subcarbonaceous, shining-black, with a 

 minute, round, perforated ostiolum, finally collapsing and umbilicate or 

 subplicate, but never opening as in Rhytisma. Asci cylindru>clavate, 

 100-1 10 x 18-21 ft, paraphysate, membrane entire at the apex, short- 

 stipitate, soon disappearing. Sporidia biseriate, oblong-navicular, ends 

 subobtuse, 28-30 x 8-10 /i. 



On leaves of Quercus laurifolia and Q. virens. Florida and 

 Mississippi. 



T. tosta, (B. & C.) 



Rhytisma tostum, B. & C, CJrev. IV, p. g. 

 Trabutia tosta, Cke. Sytt. 1372, 



"Seated on yellow spots, thin, gyrose. only here and there pro- 

 ducing fruit-bearing perithecia which soon shell off. Undoubtedly 

 distinct, but the specimens are imperfect.'" 



On leaves of Quercus laurifolia, Alabama, 



T. erythrospora, (B. & C.) 



Rhytisma erythrosporunt, B. & C. Proc. Am. Acad. IV, p. 12S. and GreV. IV, p. 9, 

 Trabutia erythrospora, Cke. Syn. 1371. 



"Minute, opening with two or three laeiiiiae. Asci swollen. Spo* 

 ridia subfusiform, salmon-colored, apiculate at each end, 33 ti long. 

 On leaves of Quercus virens, California. 

 The manner of dehiscence indicates Rhytisma. 



THYRIDIUM, Sacc, 



Mieh. I t p. 50. 



Perithecia scattered or gregarious, immersed in the more or lesg 

 altered substance of the wood or bark, and covered above by a prom- 

 inent, black, stromatic shield, Ostiola papilliform, Sporidia.subellip- 

 tical, brown or hyaline, muriform. 



Th. lividum, (Pers.) 



Spharia livida, Pers, Syn. p. 80, 

 Teichospoia livida, Karst. Myc. Fenu. II, p. 68, 

 (Fenestella) ? livida, Winter Die Pilze No. 4251. 

 ThyridiuMV lividum, Sacc. Syll. 3991, Cke. Syn. 3981. 





