426 
C. Braunii B. & F., credited by Bornet and Flahault to Ger- 
many and Denmark, was first found in this country by the writer, 
growing upon stones in a small brook at Sharon, Mass. Later it 
was found near Bridgeport, Conn., by Mr. Isaac Holden, growing 
upon wood and stones. It also forms extended patches on rounded 
stones in a small rivulet at Cataumet, Mass. It is of rapid growth, 
forming patches which are at first small and orbicular, but later 
enlarging and confluent into broad expansions of indefinite ex- 
tent and shape, and often becoming decidedly verrucose on the 
surface. In color the patches vary from dark green to nearly 
black. The filaments are short and parallel and the structure of 
the patch resembles that of /sactis plana, but, of course, lacks the 
common enclosing matrix of that form. 
RIvuLaRIA BorNETIANA n. sp. This curious species was found 
growing on the stems and leaves of Ruppia maritima, forming 
solid spherical thalli varying from somewhat less than a milli- 
meter to something over a centimeter in diameter, according to 
age. Frequently a row of closely-placed spheres coalesce into a 
cylindrical mass 5-8 centimeters long. The thalli are of fairly 
firm consistency and vary in color from a deep bluish-black when 
young to a light olive green or pale yellow when old. They are 
not at all incrusted with lime. The filaments radiate in a regular 
fashion from the center, becoming, however, decidedly flexuous in 
the older thalli. They vary in diameter from 8-20 yz, and separate 
readily from one another on crushing. The sheath is wide and con- 
conspicuous, colorless to deep brown in color, and very much 
lamellose and ocreate above. It varies in width below from 2-4 /” 
sometimes becoming as wide as 20 ». The trichome is usually about 
4 » in diameter, but occasionally reaches 16». It is usually very 
much torulose when young, but very little so when older. The cells 
are from one-halfto five times as long as broad. The cell limits are 
distinct in younger but very obscure in the older specimens, and 
the cell contents are light blue and provided with a few scattered 
granules. The heterocysts are basal, from depressed globular to 
ellipsoidal in shape, and from 6-8 pin diameter. The terminal 
hairs are long and slender in the younger plants, but are almost 
wanting in the older ones. 
For several years this species has been found in abundance !? 
