1903] Collins,— Notes on Algae 211 
given, and it now seems that two more are to be added. There has 
recently been published an excellent paper on the Porphyras of the 
Pacific coast,! and while in most genera of algae, the species com- 
mon to the Atlantic and Pacific Coasts are so few that a monograph 
for one coast would be of little use on the other, in this case five of 
our six species are fully treated in the paper in question. The stu- 
dent is referred to this paper for full accounts of structure and 
development, and only a key for distinguishing our species, and 
an indication of localities will here be given. 
KEY TO THE NEW ENGLAND SPECIES OF PORPHYRA. 
1. Fronds monostromatic . : : i : : : ; : 2. 
Fronds distromatic 
2. Color pink to crimson, ‘fronds small and delicate, 15- -20 p thick. 
P. coccinea J. Ag. 
2. Color usually bluish or brownish pe fronds a CM large size, 
25-50 p thick . : . ; 4 3- 
3. Antheridia forming a colorless marginal zone. 
P. laciniata. (Lightf.) Ag. 
. Antheridia tormipg small elongated colorless patches among the darker 
sporocarps.  . : P. leucosticta Thuret. 
4. Fronds about E p thick. P. tenuissima (Strömf.) Setchell and Hus. 
4. Fronds 30-75 p thick, cells in cross section square to twice as long 
as broad. : . P. miniata (Lyng.) Ag. 
4. Fronds 50-80 p thick, cells in cross section square to somewhat 
higher than br EA P. amplissima (Kjellm.) Setchell and Hus. 
The thickness of the frond is taken in the middle of the vegeta- 
tive part; near the base the frond is often considerably thickened. 
P. coccinea has been found only once in America; it grew on a frond 
of Desmarestia aculeata washed ashore at Hampton, New Hampshire. 
It has the distinction of being the only species of algae recorded for 
the little strip of New Hampshire coast, but not found in any other 
New England state; it is hardly likely that it will retain this distinc- 
tion permanently. P. /aciniata is a cosmopolitan species, found 
throughout our range, and quite variable in form and color. The 
type ranges from lanceolate to much laciniate in outline ; in addition 
to this we have forma wmbi/icafis Ag., with umbilicate fronds, often 
much plicate; this seems to be common on exposed rocky shores 
! Henri T. A. Hus, An Account of the Species of Porphyra Found on the 
Pacific Coast of North America. Proc. Calif. Acad, Sci., 3d Series, Botany, Vol. 
TI p 173 (1902). 
