6 4 - 
pointed out that calcareous lichens with Chroolepus gonidia can dissolve calcium 
carbonate and that a limestone will thus become perforated in a sponge-like 
manner by the Chroolepus cells. 
Conklin’s Hepaticae of the Duluth Superior District. — Under the 
title of “Preliminary Report on a Collection of Hepaticae from the Duluth- 
Superior District” (Trans. Wisconsin Acad. Sci., Arts, and Letters 17 : 985- 
1010. Reprint, Oct., 1914) Dr. Geo. H. Conklin, Curator of the S. M. S. Hepatic 
Herbarium, has published an annotated list of the hepatics found within a radius 
of about fifty miles from the two towns, Duluth and Superior, at the extreme 
west end of Lake Superior. The first four pages of this excellent paper are de- 
voted to a good description of the physiography and general geology of the 
district, while following this is the catalogue of species, eighty-two in all, with 
many interesting critical notes on their general characteristics and habitats. 
The Twentieth Anniversary of the New York Botanical Garden 
will be commemorated at the Garden during the week commencing September 
6, 1915. Botanists from all parts of North America are invited to attend. The 
program for the week will be a notable one, including reading and discussion of 
papers, inspection of buildings and grounds, and visits to study the coastal flora 
of Staten Island, the pine barrens of New Jersey, and the Brooklyn Botanic 
Garden. Readers of The Bryologist should keep this in mind. 
The veteran collector and botanist, Dr. John Macoun, is now living at Sid- 
ney, Vancouver Island, and is collecting more particularly the thallophytes 
and bryophytes of that interesting region. 
The Editor, accompanied by his wife, is this season taking advantage of 
the low fares to visit Washington State for a general botanizing and collecting 
trip. The plan is to spend some time in each of the general floral areas, begin- 
ning in the Spokane district about June 20, and reaching the western end of the 
state about the middle of September. Most of the time will be spent in a tent 
in more or less out-of-the-way places, but first-class mail will be forwarded 
either from the regular address at the Carnegie Museum, Pittsburgh, Pa., or 
from Spokane. 
Both the July and September numbers of The Bryologist will be late on 
account of the inability to keep in touch with the mail, and because of distance 
from headquarters. We would beg the indulgence of our readers for the delay. 
EXCHANGE DEPARTMENT 
Offerings to S. M. S. members for stamped self-addressed envelope: 
Mr. Severin Rapp, 207 First St., Sanford, Florida. — Lobadium phyllocharis 
Merrill, Lobadium vulpinum (Tuck.), and Arthothelium macrothecum (Fee). 
Mr. Chas. C. Plitt, 3933 Lowndes Ave., Baltimore, Maryland. — Cetraris 
Oakesiana Tuck. 
Mr. Roy Latham, Orient, Long Island, N. Y. — Xanthoria parietina (L.) 
Th. Fr., Usnea florida (L.) Hoffm., and U. trichodea Ach., all from Long Island. 
Dr. H. E. Hasse, Santa Monica, Cal. — Opegrapha vulgata Ach., collected 
:In California. 
