Durand: The Genus Keithia 
11 
Garden. The material from Lake Sunapee is more mature than 
the rest, and shows spores conspicuously colored. This charac- 
ter, as well as the tetrasporous asci and the spores divided into 
two very unequal cells, indicates its close relationship to K. tetra- 
spora and K. thujina. The covering epidermis falls as a scale as 
in the last named species. 
Dr. Davis’s recent collections are also mature and agree in all 
respects with those from New Hampshire. 
Dr. Farlow informs me that since he first found it, in 1882-3, 
he has secured more mature material in several localities, which 
has quite modified his original view regarding this species. In 
the type the spores are immature and hyaline, and through an 
error were described as 8-spored instead of 4-spored. Compari- 
son with authentic Keithia tetraspora, in Europe, convinced him 
that his Stictis Tsugae is congeneric, and should be called, there- 
fore, Keithia Tsugae. 
The same writer speaks of the parasitism of this species as fol- 
lows : “ The fungus appears only on the under side of the leaves, 
which turn brown and quickly fall. It was first noticed in Au- 
gust, 1882, on a tree affected with Peridermimn Peckii. In Sep- 
tember, 1883, it was found on a large number of trees, and had 
nearly destroyed the foliage. It may be considered a disease 
which does considerable harm.” 
On the basis of observations recently made upon this species in 
Wisconsin, Dr. Davis entertains some doubts about its parasitic 
nature. He has found no instances in which it appeared on 
undoubtedly living leaves, and he is convinced that it is not so 
certainly parasitic as is K. thujina. 
University of Missouri, 
Columbia, Mo. 
Explanation of Plate LXXXI 
Keithia thujina. Fig. i. Portion of branch of Thuja showing four asco- 
mata. X 6. Fig. 2. Single ascoma much enlarged showing the epidermal scale 
falling away. Fig. 3. Asci, paraphyses and spores. Figs. 4-5. Asci, paraphyses 
and spores drawn with the oil immersion objective. 
Keithia tetraspora. Fig. 6. Portion of leaf of Juniperus showing two asco- 
mata exposed by the stellate splitting of the epidermis. Fig. 7. Three asci, 
paraphyses and spores. Fig. 8. Three spores more highly magnified. 
Keithia Tsugae. Fig. 9. Leaf of Tsuga showing nine ascomata, much 
enlarged. Fig. 10. Single ascoma greatly enlarged exposed by falling epidermal 
scale. Fig. ii. Asci, paraphysis and spores. 
