34 
No. 223. E. constricta. Branched and much constricted at irregular inter- 
vals. 
Summer, parasitical, on other Algae, and on pebbles and shells, on mud flats. The finest specimens 
grow on the flats at Communipaw, attached to clam, mussel and razor shells; this variety adheies well to 
paper, while that growing on Fucus, shrinks, cracks, and darkens, in drying. The plants of this genus aie 
much varied in form : our waters seem congenial to its growth, and teem with innumerable vaiieties that cor 
respond with all the numerous species described by European algologists. I think, howevei, that a further 
enumeration of species would not improve the science, and indeed, I am not sure, that to suppress compressa 
and ramulosa, leaving the whole under the species intcstinalis and constricta , or under intestinalis, variety 
constricta , would not be an improvement. 
Genus,. ULVA. L. 
Green, flat, sometimes inflated in tbe young state ; fructification as far as known, 
zoospores direct from the endochrome in the cells. 
No. 230. U. latissima. L. Broadly ovate, flat.' 
May to February, very abundant, on rocks, stones, shells, and parasitical; 3 inches to 5 feet long; the 
largest specimens grow on flats at Gowanus and Communipaw : this plant bleaches in decay to a cream 
color or white, and some specimens are exceedingly beautiful in that state. 
No. 231. U. lactuca. L. At first obovate, inflated, at length cleft down to 
the base, the segments unequal and laciniated. 
Summer, on Fucus and other Algae, between tides, and on rocks and shells in all parts of the Harbor. 
No. 232. U. linza. L. Linear-lanceolate, acute, composed of two membranes 
closely applied. 
Summer, parasitical, on Fucus, at half tide, when it is from 3 to 15 inches long, and undulate at the 
margin. A variety, from 3 inches to 10 feet in length, perfectly plane and linear, grows on the flats at 
Gowanus and Communipaw, attached to pebbles and shells. It is very abundant for a short season. 
Genus, PORPHYRA. Ag. 
Purple, plane, thin; fructification, circular sori from aggregated cells. 
No. 235. P. vulgaris . Ag. Ovate or linear, simple or cleft, or waved in the 
margin. 
Spring, on rocks and pebbles from half tide to low water mark, very abundant. We have several va¬ 
rieties in form; beautiful clusters, linear, 15 inches long, are found at Kavon Point; broadly ovate, plane or 
with waved margins from 2 to 12 inches long, at Jersey City and elsewhere ; with deeply cleft segments, 
(the Jaciniata of Lightf.,) are abundant at Castle Garden. The purple color is instantly changed to green by 
caustic, potash, or by ammonia; the color appears to emanate from the endochrome or contents of the cells; 
the walls of the cells are broad and rather pellucid, giving the shriveled endochrome the appearance of 
“ roundish granules, mostly arranged in a quartate manner, and covering the whole plant,” described by 
Greville as a second form of fruit. The fruit is evidently from the sori, or circular aggregation of cells ; the 
conglomeration begins at the periphery, which is densely opaque, while the centre continues to show the dis¬ 
tinct outline of the cells; the whole circle, however, finally becomes fructified, and is then entirely opaque. 
This plant, under the names of Lavor , Slo7ce, or Slokum , is used as food in many parts of Great Britain • it 
is reduced to a pulp by stewing for several hours, and when served with lemon juice, is said to be a favorite 
dish with many persons. 
