750 The American Naturalist. [August, 
The apparent absence in California of Bazzania and Mylia, which 
are especially characteristic of medial and boreal regions, serves to 
heighten the similarity to southern Europe. 
The paper was followed by exhibit of photomicrographs of sections 
of Cryptomitrium, illustrating the development of the archegonia. 
In the discussion following, Prof. Underwood said that Hepatic spe- 
cies are most numerous in the Amazon region and the eastern slope of 
the Andes and in Java. Insular tropical regions have furnished many 
where examined, as Cuba and Jamaica. Quite a number are peculiar 
to Australia. New Zealand is well-supplied with species. Many have 
been recently collected in Africa, and have been described by Herr 
Stephani, of Leipsic, whose industry has doubled the number of de- 
scribed Hepatic. As a whole, the maximum development of the 
Hepatic is tropical, though some genera and certain groups within 
genera are wholly high-temperate or subarctic. 
Prof. Britton remarking the indications of circumboreal and circum- 
tropical distribution of certain species, referred to the argument for an 
equatorial distribution of flowering plants and of ferns, and queried if 
there were anything corresponding among Hepatice. He expressed 
the belief that it is the immediate environment which at present exerts 
the principal influence on distribution, whatever the original cause OF 
mode of distribution may have been. 
Prof. Underwood referred to the influence of the Gulf Stream in 
permitting the existence of the subtropical genus Lejeunia on the coast 
of Ireland, a genus not elsewhere found in Europe. Comparing the 
Hepaticæ of Florida, they are only in part known; a few species are 
in common with the Appalachian flora; most of the Florida hepatica 
are close-creeping forms found on bark, as Frullania and Lejewnia, - 
having water sacs on their leaves as aid in resisting drought. Some 
tropical Marchantiacee occur in Florida, and also, especially, species of 
Riccia and Anthoceros. Thallocarpus is known only from Florida and 
South Carolina. Adjourned to May 26. 
' May 26, 1897.—The President, Hon. Addison Brown presided. ‘The 
evening was devoted to a lecture by Mrs. Elizabeth A. Britton, entitled 
“ The Moss Flora of the Adirondack Mountains,” illustrated by lan- 
tern slides prepared by Mr. C. H. Van Brunt, and also by about 150 
mounted sheets displaying specimens collected by Mrs. Britton in the 
vicinity of Adirondack Lodge and Lake Placid in the years 1892, 1894 
and 1896. Their various habitats were described, with the story of ® 
climb up Whiteface. About 30 rare species were enumerated, includ- 
ing Raphidostegium jamesii not previously reported from New York 
