26 
INTRODUCTION. 
IV. 
resemblance to that of the shores of Iceland, Norway, Scotland, and the North 
and North West of Ireland. 
2nd. Long Island Sound, including under this head New York Harbour and the 
sands of New Jersey. 
The natural limit of this region on the south is probably Cape Hatteras, but 
after passing New York the almost unbroken line of sand is nearly destitute of 
Alge. I have not received any collection of sea plants made between Long 
Branch and Wilmington. In comparing the plants of the sound with those of 
our 1st region, a very marked difference is at once seen. We lose the Arctic 
forms, Agarum , Rliod. cristata , Odonthalia , Dumontia ramentacea and Ptilota plu- 
mosa , whose place is supplied by Sargassum , of which genus two species are 
found at Greenport and at other points in the Sound ; by various beautiful Cal- 
lithamnia and Polysiphonice ; and by abundance of Delesseria Americana and 
Dasya elegans. Those two latter plants are not limited to this region, but are 
greatly more abundant here than north of Cape Cod. Del. Americana seems 
almost to carpet the harbour of Greenport, and is equally abundant in various 
points in the Sound, and Dasya elegans grows to an enormous size in New York 
Harbour, and is plentiful throughout the region. Seirospora Griffiths iana is not 
uncommon; it grows luxuriantly at New Bedford, whence Hr. Roche has sent me 
many beautiful specimens of it, and of other Ceramiece. Phabdonia Baileyi , Gracila- 
ria multipartita , (narrow varieties) Ckrysymenia divaricata and C. Rosea are also 
characteristic forms. Delesseria Leprieurii , found in the Hudson at West Point, 
scarcely belongs to this region, but is a tropical form at its utmost limit of 
northern distribution. 
3rd. Cape Hatteras to Cape Florida. Of the Algae characterizing this region 
we know little except those found in the neighbourhood of Charleston, and a 
few specimens collected at Wilmington, N. C. and at Anastasia Island. Many 
species found within these limits are common to the second region ; others are 
here met with for the first time. Of these the most remarkable are Arthroclaclia 
villosa and a Nitophyllum , found at Wilmington ; a noble Grateloupia, probably 
new ( G. Gibbesii , MS.J found at Sullivan’s Island, and Delesseria hypoglossum, 
already mentioned as occurring at Charleston and Anastasia Island. I have seen 
no Fucoid plant from this region ; but if there were a suitable locality, Ave ought 
here to have Sargassa. None grow at Sullivan’s Island, where Grateloupia Gib- 
besii is the largest sea plant, and the one most resembling a Fucus. All the estu- 
aries of this district produce Delesseria Leprieurii , and a Bostrychia , either B. 
radicans , Mont, or a closely allied species. These last are tropical forms first 
noticed on the shores of Cayenne, where the former was found both on mari- 
time rocks, and on the culms of grasses in the estuary of the Sinnamar river. 
With us these plants groAv on the palmetto logs in Charleston Harbour, and on 
Spartina glabra as far up the river as the Avater continues sensibly salt. 
Del. Leprieurii was collected by Hr. Hooker at NeAv Zealand, accompanied by a 
Bostrychia. No other habitats for it are knoAvn. 
4th. Florida Keys, and Shores of the Mexican Gulf. Here w r e have a very 
