90 Rhodora [May 
S. fluctuans (Morong) Robinson may be expected in the larger 
ponds and lakes of northwestern Rhode Island. 
S. lucidum Fernald & Eames, as yet known only from eastern 
Massachusetts, Pennsylvania, Illinois and Missouri, is probably in 
Rhode Island and Connecticut. 
S. minimum Fries may be confidently sought in clear cold streams 
of northern New Hampshire. 
S. simplex Huds. is apparently rare in northern and central Maine 
and northern Vermont, but it should be sought in all the larger lakes 
of northern New England. 
GRAY HERBARIUM. 
CAUSES OF VARIATION IN COLOR IN SOME RED 
ALGAE. 
WILLIAM A. TERRY. 
For many years past I have noticed a marked difference in color in 
specimens of red algae from different localities; this is specially 
noticeable in Dasya elegans (Mart.) Ag.; plants from South Beach, 
a mile or more east of the entrance to New Haven harbor, always 
drying a sepia brown, while those from below Woodmont, some miles 
west, dry a dark purple, and those from Fort Hale, inside the harbor, 
show a bright crimson pink color. These differences are constant, 
and have shown themselves so for many years. My specimens are 
taken, when possible, directly from the rocks on which they grow; 
they are generally procured by wading at lowest tide, but sometimes 
from a boat by means of a sharp-edged scraper with a long handle. 
Such specimens are much deeper in color than those from shallow 
water. When broken from their holdfasts they change rapidly in 
color, in a few hours showing a decided tinge of brown. All these fine 
red seaweeds, if mounted in salt water, lose their characteristic color 
from the concentration of the salt, and become more or less black. To 
obviate this as much as possible, I lay out and cleanse the plant in a 
dish of salt water, then transfer on the cardboard to a mounting board 
in fresh water, rapidly place and lift out of the water, drain slightly 
and place in driers which are changed frequently until dry. In this 
