2 Rhodora [JANUARY 
attention to the fact that Cape Cod does not sharply and exactly 
divide the northern from the southern marine flora of New England 
and proceeds to add much to our knowledge by discussing the reasons 
for this imperfect division. He says (loc. cit. p. 3, et seq.):—“ If we 
regard the marine vegetation of the northeastern United States as a 
whole, we see that, beginning at Eastport, we have a strongly marked 
arctic flora, which is a direct continuation of that of Greenland and 
Newfoundland. As we proceed southward towards Boston, although 
the luxuriance of growth is less, the general appearance of the flora is 
still unmistakably arctic, if we except a few sheltered localities. The 
northern shore of Cape Cod, from its sandy character, is practically 
destitute of all species of algae, except a few forms which are here and 
there found growing on the eelgrass. As soon as we pass to the south 
of Cape Cod, however, the flora assumes an entirely different aspect. 
The arctic and Northern European forms have disappeared, except at 
a few exposed points like Gay Head and Montauk, and in their place, 
we find a number of species, as Dasya elegans, Rhabdonia tenera, 
Chondria tenuissima, Sargassum vulgare, characteristic of warmer 
seas." A little farther on, he goes on to say:—‘ It will be seen that 
Cape Cod is the dividing line between a marked northern and a south- 
ern flora. In fact, the difference between the florae of Massachusetts 
Bay and Buzzards Bay, which are only a few miles apart, is greater 
than the difference between those of Massachusetts Bay and the Bay 
of Fundy, or between those of Nantucket and Norfolk. This differ- 
ence in the flora corresponds precisely with what is known of the fauna. 
That Cape Cod formed a dividing line was known to Harvey, and 
subsequent observation has only shown, on the one hand, that the 
flora north of Cape Cod is more decidedly arctic than he supposed, and 
that, on the other hand, south of the Cape it is more decidedly that of 
warm seas. The general fact of the distinctness of the two florae is 
not weakened by the knowledge that we now possess, owing to the 
investigations of the Fish Commission, of the existence in a few 
sheltered localities north of Cape Cod of some of the characteristic 
species of Long Island Sound and, in a few exposed spots south of the 
cape, of northern species. Of the more common species found along 
the whole coast of New England, by far the greater part are also 
common in Europe. . . . But a very few exclusively American 
species are found throughout our limits. Most of the purely American 
species are either confined to the shore south of Cape Cod or else to the 
shore from Boston northward.” 
