OSCILLATORIACEAE 17 
haps more suggestive of Reinsch's figures of Sphaenosiphon incrus- 
tans than of his figures of S. prasinus. Тһе specimens on Chaeto- 
morpha and Cladophora from the Chincha Islands are remarkable 
for their color, which is a light bright green, sometimes with a 
slight tinge of blue. Тһе color in these may have undergone some 
change owing to the action of the formaldehyde solution in which 
the plants are preserved, though certain other associated Cyano- 
phyceae retain a, pronounced bluish color. It is to be noted, too, 
that the specific name prasina and the original description of the 
species call for a dominant degree of green, though all of the 
specimens labeled D. prasina that we have examined have seemed 
to us to be decidedly blue. It may be observed, also, that the 
epiphyte on Sphacelaria, from which most of Reinsch's figures 
were drawn, may fairly be considered the type of the species, 
rather than the epiphyte on Catenella from which the sixth and 
last of Reinsch's figures and all of the figures subsequently pub- 
lished by Bornet and Thuret were drawn. Іп the way of further 
description of the greenish form (196 p.p.) it may be added that 
the colonies are irregularly diffluent or pulviniform or suborbicular, 
and are mostly 80-500 и in diameter; the young cells аге discoid 
and polygonal, 3-5 и in diameter, often showing more or less 
distinct rows at the margin of the colony; the mature cells are 
short-prismatic, subcylindric, clavate, or trumpet-shaped, 13- 
27 и X 6-14 u, truncate, rounded-obtuse, or subacute; the cell 
wall is thin (about 2 и thick). Тһе cells show a great variety in 
form and size and commonly a striking differentiation between 
sterile and fertile cells, but these characteristics seem to obtain 
also in the genuine D. prasina. In the younger conditions the 
small cells at the margins are often in rather easily recognizable 
rows, which would appear to indicate vegetative division and would 
perhaps be considered by some a sufficient ground for placing the 
plant under the generic name Хепососсиз, but this alleged distinc- 
tion between Хепососсиз and Dermocarpa, in our opinion, does not 
exist in nature. Vegetative divisions appear to occur in both. 
Family OSCILLATORIACEAE 
" Lyngbya ferruginea var.? Ag. . . . An species distincta?” has 
been reported from the Peruvian shores by Montagne (Fl. Boliv. 3. 
