26 INTRODUCTION. IV, 



resemblance to that of tlie 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 

 Al^ae. I have not received any collection of sea plants made between Long 

 Branch and Wilmington. In comparing the plants of the sound Avith those of 

 our 1st reo-ion, a very marked difference is at once seen. We lose the Arctic 

 forms, Agarum, Rhod. cristata, Odonthalia, Dumontla 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 Griffiilisiana is not 

 uncommon; it grows luxuriantly at New Bedford, whence Dr. Roche has sent me 

 many beautiful specimens of it, and of other Ceramiece. Rhabdonia Baileyi, Gracila- 

 ria multipartita^ (narroAV varieties) Chrysymenia 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 Hatteeas to Cape Florida. Of the Algte 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 Arthrocladia 

 villosa and a Nitophyllum, found at Wilmington ; a noble Grateloupia, probably 

 new (G. Gibbesii, MS.) 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, we 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 sestu- 

 aries of this district produce Delesseria Leprieurii., and a Bostrychia, either £. 

 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 asstuary of the Sinnamar river. 

 With us these plants grow on the palmetto logs in Charleston Harbour, and on 

 Spartina glabra as far up the river as the water continues sensibly salt. 

 Del. Leprieurii was collected by Dr. Hooker at New Zealand, accompanied by a 

 Bostrychia. No other habitats for it are known. 



4th. Florida Keys, and Shores of the ]\Iexican Gulf. Here we have a very 



