yJ P 11 e p a c e . 



tlicnisolvcs a spocial study. As I liavc paid no attention to these plants, they are 

 of course not included in this memoir. 



In the synonymy I have generally followed Trof. llabenhorst. The original de- 

 scriptions of tlie forms, especially those of the older authorities, are very frequently 

 so meagre and obscure, that the species cannot be recognized by them Avith any cer- 

 tainty. VroL Rabenhorst has gone over the ground most carefully, with access to 

 the whole literature of the subject <and probably to all extant type specimens, and his 

 decisions are, no doubt, as accurate as the circumstances will allow. To attempt to 

 diifcr from them, to go behind his work to the original sources and make fresh 

 interpretations, would cause endless confusion. I have, therefore, nearly always 

 contented myself with his diclum, and have referred to him as the authority for the 

 names used. 



The following references were omitted through a misunderstanding from the first 



portion of the text. 



Page 14. Ciil<t!<pha:Tium duhium, Grunnow. Rabeniiorst, Flora Europ. Algarum, Sect. I. p. 55. 



" 15. Mei-ixmopedia convolula, Brebisson. Rabe-NDORST, Flora iJurop. Algarum, Sect. I. p. 58. 



" 18. OsciUaria chlorina, KIjtzing. Rabenhorst, Flora Europ. Algarum, Sect. I. p. 97. 



" 18. 0. Frohlichii, Kutzing. Rabeniiobst, Flora Europ. Algarum, Sect. I. p. 109. 



" 19. 0. nigra, Vauciier. Rabenhorst, Flora Europ. Algarum, Sect. I. p. lOt. 



" 19. 0. limosa, Agaruh. Rabenhorst, Flora Europ. Algarum, Sect. I. p. 104. 



" 21. Chthonoblastus repens, Kutzing. Rabenhorst, Flora Europ. Algarum, Sect. I. p. 1.32. 



" 22. Lyiujhija muralis, Agardh. Harvey, Nereis Boreali- Americana, pt. III. p. 104. 



In tlie text after the "■Habitat,'" a name is quoted as the authority therefor; if 

 such a name be in brackets, it signifies that the specimens were simply collected by 

 such individual, but that the identification was made by some one else ; when there 

 is not a name unuidoscd in brackets, it is meant that the identification was made by 

 the author of this memoir. 



Since the present memoir has gone to press, I have received from the author a 

 copy of " Alg;t! Khodiacese. A list of Rhode Island Alg?e, collected and prepared 

 by Stcplien T. Olney, in the years 184:6-1848, now distributed ixoin his own her- 

 barium." 



In the introduction to this list, Mr. Olney says: "Of the fresh-water species, I 

 have few for distribution. These were obtained mainly in the environs of this 

 city, and were placed in twenty-seven small vials in Goadsby's solution, and sent 

 to Prof Harvey, who submitted them to the judgment of the most learned Eng- 

 lish botanist in this particular department, G. H. K. Thwaites, Esq., then of Bris- 

 tol, England. The large number of species found in this collection, in so limited 

 a range, and collected within a very short period, is surprising, and shows what 

 moie persistent collections will develop. I have not time to collate the numerous 

 pubUcations of the lamented Prof. Bailey, or I might have made the list of this 

 portion of Rhode Island plants more complete." 



The chlorosperms of this list are as follows: — 

 Porphyra vulgaris, Ag.-IIarv. Ner Bor. Am. 3. 5.3. Newport 

 Bangiafuscopurpurea, Lyngb.-Harv. Ner. Bor. Am. 3. 54. Southern Rhode Island. 



