472 
JOHN A. ELLIOTT 
large percentage of the species of Alternaria and Macrosporium de- 
scribed in the "Sylloge Fungorum" and found in the exsiccati. No 
variations occurred in the forms in group <5, of the exsiccati material 
studied except those which would occur due to age, and all in this 
group might be considered A. tenuis and varieties of A. tenuis. Even 
the narrowest limitation in the application of specific names would 
preclude the retention of many of the present species. 
No final disposition of the present specific names of Alternaria and 
Macrosporium can be made without a study of authentic specimens 
of each species. Most of the descriptions are far from being complete 
or definite enought to permit their being used for this purpose. For 
convenience a tentative grouping of similar forms which may be 
identical, and which are undoubtedly closely allied, should be made. 
These groups might well be retained to indicate the similarity of a 
number of forms such as is exemplified in bacteriology in the B. coli 
and B. suhtilis groups. As in bacteriology, each group should be 
designated by a typical species. 
The groups suggested are as follows: 
The A . tenuis group. This group is characterized by spores ranging 
from 11-50 X 7-20 11. The spores are quite variable in form as well 
as in size but are generally broad and muriform (fig. i, spores of the 
A. tenuis group). All specimens mentioned in group 6, page 446, 
belong here. 
The A. brassicae group. This group should contain regular, long, 
tapering, acute-beaked spore forms with measurements ranging from 
35-120 X 10-30 ju. The spores have few longitudinal septa and are 
often long beaked (fig. 2, spores of the A. brassicae group). All of 
group J, page 444, belong in this group. 
The A. herculea group. A. herculea (E. & M.) com. nov. (Macro- 
sporium herculeum E. & M.) is the type of a group with spores similar 
in form to those in the ^. brassicae group but much larger (fig. 3, spores 
of the A. herculea group). To this belong the specimens mentioned 
in group 4, page 445. 
The A. cucumerina group. A. cucumerina (E. & E.) com. nov. 
{Macrosporium cucumerinum E. &. E.), syn. A. brassicae var. nigrescens 
Peglion, is typical of a group similar in spore form to that of A. bras- 
sicae but with the spores uniformly wider and more muriform and, 
generally, shorter (fig. 4, spores of the A. cucumerina group). In this 
group should be placed all in group 5, page 445. 
