NORTH AMERICAN PARASITIC EXOASCE.E. m 



dermis is entirely used up in the formation of the ascogenous 

 cells; these are distinguished, especially after breaking through 

 the cuticle, by their golden-yellow contents. 



The shape of the asci is very remarkable; they are either 

 slender, and penetrate deeply between the epidermal cells: or 

 thick, and round at the b;.se. which is slighth' immersed: 

 they are clavate, rounded usually at the apex, somewiiat 

 attenuated at the point of extrusion through the cuticle. x\t 

 the base of the slender forms there is sometimes a stalk-cell, 

 but in the thicker ends this is generally absent. 1 have never 

 observed them in the American specimens, and but seldom in 

 the European. 



The spores may reacii a diameter of 4//, but are said 

 to never all develop. For the determination of this species, 

 having no American exsiccati. I made comparisons with 

 affected leaves of P. ii/o-ra, sent me by Prof. Sadebeck, with 

 Taphrina anrca Tub, Rathay Flora Austro-Hungarica 117^5, 

 Bxoasnis popiili de Thiimen Mycotheca Universalis 80,. 

 Asconiyccs aureus (Pers. ) Magnus, Saccardo Mycotheca ven- 

 eta 1500. Rabenhorst Fungi Europa^i 2350 and others. 



TxPHiiiNA joHANSONii .SV/i/r/;rr/(-. Plate III. Fig. i. 

 Bib), and Svn. : 



Ascoiuyccs aureus Auct. Amer. 



Thiimen "79. 

 Ilarkness '85. 



Tapliriiia aurea Auct. Amer. 



Faiiovv "78. Ellis A: E\ eiiiart "87. 



Ellis '79. Robinson '87. 



Farlow "83. Ellis '89. 



Peck '86. 



Taphrina rhizophora x\uct. Amer. 



Farlow li; Seymour \yj. Davis '93. 



Seymour & Earle '92. 



Tap/ir/iia jolumsouii Sadebeck "90. 



Sadebeck '93. 



