112 TENTH ANNUAL REPORT OF 



wliich ftimily several are peculiar to the American shore, the roost re- 

 markable of which is the Agarum or Sea Colander. 



Among the red Algae (or Bhodosperms) , species with expanded, 

 leaf-like fronds are proportionably less numerous than on the Euro- 

 pean side. Delesseria sanguinea is absent on the American shore, 

 Avhere its p^ace is supplied by D. Anv^ricana, a species of equally bril- 

 liant coloring, but lower in organization, connecting Delesseria with 

 NyfopJnjUum. This latter genus, of which there are so many fine 

 European species, is scarcely known in North America. A few scraps 

 of Nytophylla (almost too imperfect to describe), picked up at the 

 mouth of the Wilmington river, N. C, and at Key West, are all the 

 evidence we at present possess of the existence of that type of form 

 on tlie North American shore, riocamium coccineuon, so abundant in 

 Europe, and which is also widely dispersed in the Southern ocean, 

 extending from Cape Horn eastward to New Zealand, has not, that I 

 am aware of, been found on the American Atlantic coast, Avhere its 

 place seems taken by the equally brilliant Ehodymenia cristata, 

 Ceramiwn ruhrum is as common on the American as on the European 

 coast, and many of the other common American Ehodosperms are na- 

 tives of both continents. 



The Green Alga3 {Chlorosperms) are still more alike; but several of 

 the American Cladophoras (not yet fully explored) seem to be peculiar. 

 Codium tomentosum, which is common to the shores of Europe from 

 Gibraltar, in lat. 36°, to Orkney in lat. 60°, and perhaps further north, 

 has yet been found only on the Florida Keys, (lat. 24°). Judging 

 from its distribution in other parts of the world, particularly in the 

 Pacific and Southern Oceans, one would have expected to find it all 

 along the East coast of North America. 



Perhaps it would be premature to indicate regions of Algfe into 

 which the Eastern and Southern shores of the North American States 

 may be divided, a few points only having as yet been carefully ex- 

 plored. Halifax harbor, Massachusetts Bay, Long Island Sound at 

 several points from Greenport to New York, New York harbor, and 

 the neighborhood of Charleston, S. C, are the chief points at wliich 

 the materials for my essay have been collected on the East coast. Our 

 knowledge of southern Alga? is at present derived chiefly from a par- 

 tial examination of the Florida Keys, by Dr. Wurdemann, Professor 

 Tuomey, Dr. Blodgett and myself. I think it probable, however, 

 that future researches will indicate four regions of distribution, as 

 follows : 



1st. Coast north of Cape Cod, extending probably to Greenland. 

 Among the characteristic forms of this region are the great Laminarias, 

 particularly L. Longicruris, one of the largest Algae on the coast, and 

 Agarum Turneri and pertusum. Several of the rarer Fucaceas seem 

 also to be confined to this district. One of the most abundant and 

 characteristic species of this tract is Rhodymenia cristata, which has 

 not to my knowledge been found farther south than Cape Cod. Speci- 

 mens said to have come from Staten Island have been shown to me, 

 but the evidence on which the habitat of these rests is not satisfactory, 

 and none of the Brooklyn and New York Algologists (a numerous 

 and indefatigable band) have yet detected the plant in their harbor. 



