400 BRITISH DISCOMYCETES. 



b. The mycelium spreading only between the 



epidermal cells and the cuticle of the 



young shoots. 

 (a) Asci furnished with a stem-cell . . species 5-7 

 C. Species the position of which is at present 



uncertain . . . . . . . . ?> 8> 9 



Key to the Species. 



On trees . . • • • • • • • • . . 1 



On herbaceous plants. . .. .. .. ..2 



On leaves of Alnns glutinosus : sporidia 8 . . _ . . Tosquinetii. 

 On female catkins of Alnus glutinosus : sporidia 



more than 8 . . . . . . . . • • • • Ami. 



On leaves of Juglans regia Juglandis. 



On bra iches and leaves of Betula alba . . . . turgidus. 



On leaves of Pyrus communis, Crataegus Oxycantha, 



and G. monogyuea . . . . . . . • • • bullatus. 



On young fruit of Prunus domestica, P. Padus, and 



P. spinosa Pruni. 



On leaves and branr-hes of Prunus avium, P. 



Cerasus, P. domestica, P. Chamxcerasus, aud 



Persica vulgaris, P. amygdalus, and P. communis deformans. 



Poteutill i Tormentilla Potentillaz. 



Trientalis Europeea Trientaltis. 



9 /° Q 



" \On 



A. PERENNIAL MYCELIUM SPREADING THROUGH THE IN- 

 TERCELLULAR SPACES OF THE YOUNG SHOOTS OF THE 

 INFECTED PLANT IN SPRING. 



(a) Asci furnished ivith a stem-cell. 

 1. Ascomyces Pruni. (Tul.) 



On unripe fruit of Prunus domestica, spinosa, and 

 Padus, deforming them ; asci oblong-clavate, rounded or 

 truncate at the summit; sporidia 8, broadly elliptic, 

 about 6 x 4/x. 



Taphrina Pruni — Tul. in "Ann. Sc. Nat.," ser. 5, 

 vol. v. p. 129; Johanson, "Vet. Ac. Handl," arg. 42, 

 p. 32. Exoascus Pruni — Fckl., " Symb. Myco," p. 252; 

 Sadebeck in Rabh., " Krypt. Flo./' p. 5, fig. 3. Ascomyces 

 Prwni—B. and Br., "Ann. Nat. Hist.," No. 1629; "Gre- 

 villea," v. p. 62. 



Exs.— Fckl., "F. Rh.," 1081; Eunze, "Fung. Sel.," 

 167; Rabh., "Fung. Eur," 1167; Rehm, "Asco," 130; 

 Thum, " Fung. Aus.," 504 ; Thum, " Mycoth. Univ.," 976. 



