100 REVISION OF THE NoRTH AMERICAN HYDNACEAE 
which others are referring to the same species. Moreover, 
assuming that the species is common and well known, no field 
notes are considered necessary. As a result much confusion has 
arisen in our conception of these species. Occasionally mycolo- 
gists, who have received specimens from all parts of the country, 
have noted that certain species present remarkable variations, but 
as the material thus received is usually fragmentary, without suit- 
able notes, and is received only at rare intervals, they have gener- 
ally contented themselves with noting that the form is an unusual 
one. 
In the extensive collections of the New York Botanical Garden, 
brought together from very many different sources, the confusion 
in species is very evident. This is conspicuously seen in the forms 
referred to Hydnum imbricatum L. and H. zonatum Batsch. As 
to the former species, nearly everything with a scaly pileus has 
been referred to it, while the latter has been made to include almost 
everything with a zonate pileus. 
While herbarium specimens often clearly show that they rep- 
resent distinct species, so great is the change that these plants 
undergo in the process of drying that one rarely feels justified in 
attempting a description of new species from such material without 
satisfactory field notes. On the other hand the securing of fresh 
material or at least of ample and accurate field notes is a difficult 
and discouraging task. During six years of careful watching for 
specimens of the Æ. imbricatum allies, it has been the writer’s 
fortune to find but two of the scaly-capped forms in the field ; 
likewise but one of the forms commonly referred to H. zonatum | 
has come within his observation. Of more than forty specimens 
found in the herbaria referred to these two species, not one was 
accompanied by descriptive notes that were of any value. Yet 
we have at least a half dozen good species here represented, could 
the distinctive characters be clearly established. 
The species of this family are not only comparatively rare and 
local in distribution but they are often intermittent in appearance. 
The writer once found three different species in a space not 
over ten feet square, and a fourth in the same woods a short 
distance away. But not one of the four was found anywhere in 
that region in the next four successive years, although the ground 
was searched over repeatedly each year. 
