BASCOMBE BRITT HIGGINS 
have black ascocarps; but the fact that three forms, so evidently 
related as those under consideration, show such wide variation in 
color indicates that the color of the ascocarp is here not a character of 
generic rank. Because, however, of the morphological and biological 
differences, before mentioned, the forms are divided into three species, 
as follows: Coccomyces hiemalis to include the forms on Prunus avium, 
P. cerasus, and P. pennsylvanica; Coccomyces prunophorae n. sp. to 
include the forms on the plums (P. americana, P. domestica and P. 
insititia) ; and Coccomyces lutescens n. sp. to include the forms on P. 
serotina, P. virginiana, and P. mahaleb. For these species the following 
characterization is given: 
DESCRIPTION OF SPECIES 
Coccomyces hiemalis Higgins, Science, N. S. 37: 637 and 638, 1913. Ascocarps 
embedded in the tissue of the leaf — usually filling the entire space between the lower 
and the upper epidermis — both of which usually adhere to the wall of the ascocarp, 
scattered to subaggregate, ovate to orbicular, dark brown or black, at first closed 
but at maturity opening by irregular stellate slits on the under side of the leaves, 
125-2 lO/i in diameter; hymenium pale gray to flesh-colored; asci clavate with a long 
stout pedicellate base, and abruptly papillate apex, 8-spored, 70-95 X 11-14^; 
paraphyses filiform, septate, apex slightly enlarged, often hooked, often forked; 
ascospores linear, 33-50 X 3-5-4-5M (the smaller size given in original description 
was due to a typographical error), continuous or 1-2 septate, fascicled in large end 
of the ascus; apothecial conidia produced on short conidiophores in apothecia 
after shedding of ascospores, long, slender, 50-80 X 2.5-4/^, curved, continuous or 
1-2 septate. 
Conidial stage {Cylindrosporium hiemalis): Mycelium intercellular with small 
haustoria which penetrate the host cells; spots small, brown or reddish brown, some- 
times dropping out and producing "shot holes"; acervuli amphigenous or more 
commonly hypophyllous, subepidermal, finally erumpent exposing the spores; 
conidia elongate, curved or flexuous, 45-65 X 2,5-4/^, continuous or 1-2 septate; 
microconidia (spermatia?) produced in same acervulus in late summer and fall, 
small, continuous 4-5 X i.5m- 
Conidial stage parasitic in leaves of P. avium, P. cerasus, and P. pennsylvanica. 
Ascigerous stage saprophytic, appearing the last of April to June, on fallen leaves of 
the same hosts following the conidial stage. 
Latin diagnosis: Ascomatibus hypophyllis sparsis interdum subaggregatis, 
innatis, punctiformibus, fuscis vel nigris, ovatis vel orbicularibus, 125-250^1 lat., 
primum clausis, deinde in lacinias plures acutas dehiscentibus; disco pallido carneo 
vel grisea; ascis clavatis crassiuscule stipitatis, 70-90 X ii-i4iU, octosporis, apice 
papillato; paraphysibus filiformibus, simplicibus aut ramosis, apice recto aut curvato; 
sporidiis fasciculatis, linearibus 35-50 X 3. 5-4. 5m, simplicibus aut 1-3 septatis; 
conidiis in apotheciis filiformibus, fiexuosis, 50-80 X 2. 5-4^1, 1-2 septatis. 
Hab. In dejectis foliis Prunii avii, P. cerasi, et P. pennsylvanicae. 
