24 



I. Delesseria, Lamour. — Name, M. Delessert. 

 II. Nilupiiy Hum, Greville. — Name, shining leaf, 

 III. Plocamium, Lamour. — Name, intertwined hair. , 



Genus I. — Delesseria. Lam. 



Frond leafy, definite m form with a percurrent midrib* Con- 

 ceptacles scailered over the frond. 



D. sanguinea, Linn. Massachusetts Bay; 



D. sinuosa, Goodwin and Woodward ; Boston. 



D. Americana, Greville; N. Y. Hay, &c. 



D Hypoglossum, Woodward ; Boston. 



D. L"prieurii, Montague ; West Point. 



D. cafuglossum, Harvey ; Newburyport 



D. alala, Hudson; Lynn. 



D. involvens ; Kev West. 



1 Sp. 1 or new ; Key West. 



If. NlTOPIIYLLUM. 



Frond membranaceous, veinless, rosy red. Conceptacles sessile 

 on the frond. Tetiaspores in scattered spots. 

 N. 1 Sp.1 or new; Wilmington, IN. C. 



III. Plocamium. Lam. 



Frond linear, compressed or flat, indistinctly nerved, much 

 branched. Tubercles stalked, or sessile onlhe margin. 

 P. coccineum, Hudson ; Lynn, Massachusetts. 



Order V.— RHODYMENIACEiE. 



' Frond leafy or filiform, inarticulate. Polygonal cells. Concep- 

 tacles external, or partially imbedded in the surface. Telraspores 

 collected in undefined cloudy spots. Contains four genera, namely — 

 I. Rhodymenia, Greville. — Name, a red membrane. 

 II. Sphoerococcus, Stackhouse. — Name, sphcerical seed. 

 . III. Gracilaria. 

 IV. Hypnea. 



Genus I.— RHODYMENIA. Grev. 



R. palmafa, Greville ; Seaconnet Bav, &c. 



R. palmetto, Esper. ; Newburyport. 



R. cristata, Lamour. ; Massachusetts Bay. 



R. ciliata, Lamour; Mass Bay. 



R. mernbranifohus, Giev. ; Rhode Island. 



II. SpiiiERococcus. Stockhouse. 

 Frond two-edged, linear, much branched and cartillaginous. Fruit, 

 spherical tubercles with thick pericarp.* 



