22 



P. variegata, Ag , tubes 6 ; N. Y. Bay, &c. 



P Ifarveyi, Bailey ; Greenport, &c. 



P. Olneyi, Harvey ; Greenport. 



P. parasitica, Hudson, tubes w ; Massachusetts Bay. 



P. subiilUbsima, Montague, West Point. 



P. fasti^iata, Kothwell, lubes 16; Greenport. 



P. uiceolata, Lin., tubes 4 ; Greenport. 



P. pulvinata, Ag., tubes 4 ; N. Y. Bay. 



P formosa, Von Suhr. tubes 4 ; N. Y. Bay. 



P. gracilis, Greville, tubes 4 ; N. Y. Bay. 



¥. violacea ; Boston. 



P. Gibbesii, Harvey ; Key West. 



P. breviarticulata, Ag. ; Key West. 



P. stricta ; New York Bay. 



P. Brodcei, Grev ; Massachusetts Bay. 



9 <Sp. 1 or new. 



V, Dasya. Agardh. 



Frond cylindrical ; stems inariiculale, but the ramuli jointed and 

 single tubed. 



J), elegans, Greville ; N. Y. Bay, &c. 

 D coccinia, Hudson ; Massachusetts Bay. 

 D. pendicellata ; Rhode Jsland. 

 D. Wurdemannia, Bailey ; Key West. 

 One Species? or new ; Lynn. 



Order II.— LAURENCIACEiE. 



. Cylindrical or compressed, linear, areolated, inarticulated, branch- 

 ing fronds. Conceptacles external. Tetraspores immersed in the 

 branches or ramuli. Contains three American genera, namely — 

 I. Laurencia. Lamour — Name, in honor of M. Laurencia. 

 II. Chrysymenia. J. Ag. — Name, a golden membrane. 

 III. Chylocladia. Grev. — Name, a juicy branch. 



Genus I. — Laurencia. L. 



* Frond solid, cylindrical, branched, pinnalified, ramuli obtuse. 

 Spores in pear-shaped tufts. Tetraspores imbedded in ramuli. 



L. pinna tifida, Gwillm; Stonington. 



L. dasyphylla, Woodward ; Greenport. 



L. tennuissima, Goodwin ; New Haven. 



L. Baileyi, Montagne ; N. Y. Bay. 



L. purpurascens ; Greenport. 



L. obtusa, Lamour; Key West. 



3 Sp. ? or new. 



II. Chrysymenia. J. Ag. 



Frond hollow, filled with mucus, neiiher constricted, jointed, nor 

 chambered. Spores angular. Tetiaspores immersed in ramuli. 



