404 BRITISH DISCOMYCETES. 



(5 to 7'6/u) long, whereas in A. bullatus they are 0004* 

 inch (10/jl) (B. and Br., I. c). 



Name — From the name of the host plant. 



Dr. Masters. 



7. Ascomyces turgidus. (Sadeb.) 



Producing "nests," or "witches' besoms," on birch, 

 developing the asci in spring and summer on the under 

 side of the leaves, on which the leaves at first curl up 

 sinuously, lose the fresh green colouring of the healthy 

 leaf, and on the breaking forth of the asci appear to be 

 covered on the under side with a greyish- white hoariness. 

 The asci are 46 — 50/x long, and about 15/x broad : they 

 have a stem-cell 16 — 17^u high, and 15/x broad; they, 

 however, diminish conically downwards and penetrate 

 between the epidermal cells. The sporidia are 3 — ^ji in 

 diameter. 



Exoascus turgidus — Sadeb. in Rab., " Crypt. Flo.," 

 vol. vi p. 8. 



On Betula alba, both on the large trees and small 

 ones. From the end of May to the middle of August. 



The occurrence of "witches' besoms " are by no means 

 uncommon on birch in this country, and if they are pro- 

 duced by this fungus, as Professor Sadebeck asserts, the 

 species must be recorded here. 



C. SPECIES THE POSITION" OF WHICH IS AT PRESENT 



UNCERTAIN. 



8. Ascomyces Juglandis. Berk. 



Hypophyllous, effused, snow-white on the nerves of 

 the leaves ; sporidia ovoid, hyaline. 



Ascomyces Juglandis — Berk., " Outl.," p. 376 ; Cooke, 

 ' Handbk.," No. 2235. Gymnosporium leucospovum — 

 Mont., " SylL," p. 390. 



On walnut-leaves, Jugla.ndis regia. 



Name — From the tree on which it grows. 



