to 10 10 
240 
THIRTEENTH REPORT. 
1. 
1 . 
a. 
a. 
b. 
b. 
c. 
c. 
d. 
d. 
e. 
e. 
f. 
f. 
rr 
h. 
b. 
k. 
(G) Dothidiales. 
Dothidiaceae. 
Stroma large, brown then black, forming deformities on twigs of 
Plum and Cherry trees: Plowrightia morbosa. 
Stroma small, linear or in patches, black, on leaves of grasses, 
etc. : (2) 
% 
Spores 1-celled, hyaline : Phyllochora. 
Spores 2-celled, hyaline: _ Dothidella. 
Spores 2-celled, dark-colored: Dothidia. 
(H) SpTiaeriales. 
Growing on dung: (m ) SordaHaceae. 
Not on dung: (b) 
Perithecia on the surface of the substratum, with long hair-like osti- 
oles; no stroma: (n) Geratostomataceae. 
Perithecia with short ostioles, or if long and slender then beneath 
the bark : (c) 
No stoma present; perithecia free on the surface, or more or less 
sunken into the substratum: (d) 
Stoma present; perithecia either in groups in its surface, or deeply 
imbedded in the stroma ; stroma may be on the surface or within 
the substratum : (h) 
Perithecia free, or only in the substratum at their base: 
«/ 
(o) Sphaeriaceae. 
Perithecia sunken in the substratum, only exposing the short osti- 
oles : (e) 
Asci usually thickened at the apex; breaking open by a pore; osti- 
oles stout or elongated: (p) Gnomoniaceae. 
Asci not thickened at apex, exuding from ostioles at maturity : 
• '...(f) 
Walls of perithecia carbonaceous or thick; spores large, in a gelatin- 
ous envelope: (q) Massariaceae. 
Walls of perithecia thin, membranous-leathery: (g) 
Asci clinging together in bunches, without paraphyses: 
( r ) Mycosp haerellacea e. 
Asci separate; paraphyses present: (s) Pleosporaceae. 
Stroma spread out, margin undefined; perithecia upon it in close, ir- 
regular clusters: (t) Cucurbitaceae. 
Perithecia deeply imbedded in the stroma (k) 
Stroma formed from the changed bark or wood of the substratum; 
sometimes hardly distinguishable from neighboring wood tissue, 
sometimes sharply marked by a black line; mostly covered over 
by the bark except at point where the ostioles of the perithecia 
break through to the surface: (u) ( Valsaceae . 
( Melanconidaceae . 
