210 Rhodora [OCTOBER 
shades of brown and yellow, lightest at the margin, sometimes remind- 
ing one of a small and delicate Polyporus. Under this surface of 
vigorous fronds is a thick mass of old, overgrown fronds, the lowest 
practically a structureless mass. Probably many years’ growth is 
needed to produce one of these thick carpets. Though all the other 
species of this genus fruit abundantly, the fructification of this species 
is yet to be discovered, and the Duck Island specimens, for all their 
luxuriance, show nothing but vegetative growth. 
Turning from a rare and local species to a widely distributed and 
very common one, Polysiphonia urceolata (Lightf.) Grev. presents a 
curious form here. I can find nothing in the many descriptions of 
this plant in regard to a creeping base ; but here it formed dense mats 
of rooting filaments, from the centre of which arose the well-known 
vertical tufts. Where only the prostrate filaments occurred, no one 
would suspect, without careful examination, that the brownish cir- 
cular disk, a few centimeters in diameter, belonged to this common 
species. 
Laminaria platymeris De la Pyl. also shows different characters 
here from what it has in some other places. As noted by Setchell,! 
in Massachusetts bay it is epiphytic on the larger Laminarias; but 
here it grows on the rock sides and bottoms of the larger pools. 
In less than three hours' time, within a stone's throw of the point 
of landing, I noted sixty-one species and two varieties of algae. No- 
tice of microscopic forms was out of the question; but if we make a 
"fair allowance for them, for plants preferring the different character 
of shore which occurs in other parts of the island, and plants to be 
found at other times of the year, the number given would probably 
be doubled. It is therefore hardly worth while to give a list as 
incomplete as our present must be. The Laminariacez were strongly 
represented, both as to species and individuals, and there were five 
species of Fucus. "The general brown aspect that these large plants 
gave to the region was relieved by the green of Cladophoras of the 
Acrosiphonia group, and the pink and white of Corallina and Litho- 
thamnion. Most of the red algae were dull colored, but there were 
some superb broad fronds of Rhodymenia palmata (L.) Grev., half a 
meter in length, each frond full of tetraspores throughout ; while small, 
but bright, fronds of Polysiphonia urceolata (Lightf.) Grev., and of 
Gloiosiphonia capillaris (Huds.) Carm., lighted up the shallow pools. 
! Rhodora, Vol. II, p. 143. 
