Failow.J 35t) [May 2, 
NOTE ON AGAKICUS AMYGDALINUS M. A. CURTIS. 
The general o[)inion among mycologists is that the character- 
istics of the common mushroom are so marked that there is never 
any difficulty in distinguishing the species. This opinion is in 
general correct, but, nevertheless, forms are occasionally met with 
which vary from the ordinary described type of Agaricus cam- 
pestris, and one is not altogether certain whether such forms are 
varieties of the typical form, or should rather be regarded as 
distinct species. The question is of interest not so much from 
an economic point of view — for such forms are all probably 
edible — as from the more scientific point of view of what should 
be regarded as specific marks in fungi of this kind. In this con- 
nection a few words should be said with regard to a form of 
mushroom which has lately attracted some attention. 
I recently received from Col. "Wright Rives of Washington, 
D. C, a quantity of fungi resembling somewhat the ordinary 
Ag . campestris and somewhat the horse mushroom, Ag. arvensis, 
a species characterized by having a double ring. The fungi made 
their appearance in large quantities in a greenhouse used for 
forcing cucumbers. Colonel Rives noted an odor and taste of 
almonds not found in the common mushroom. The fungi seemed 
to me to be the same as those described by Peck under the name 
of AgaricuH siobrufescens in his report as State Botanist (4:6th 
ann. rept. regents N. Y. stnte mus., 1893, p. 105. Separate: 
p. 25), from specimens received from Mr. Wm. Falconer of 
Glen Cove, L. I. An extended notice of the fungi was given by 
Mr. Falconer in the American florist of Feb. 22, 1894. Not to 
mention less striking characteristics, Ag. suhrufescens is espe- 
cially distinguished by its ring, which is not simply a membrane as 
in Ag. campestris nor a double membrane as in Ag. aruensis, but 
rather a thick membrane, smooth above and marked below by 
distinct floccose scales. If we can conceive a complete and per- 
manent consolidation of the two membranes found in the ring of 
Ag. arvensis we should have a ring much like that actually found 
in Ag. suhrufescens. 
It is not necessary in this place to compare in detail the rela- 
tions of Ag. suhrufescens to varieties of Ag. campestris found in 
