4i6 TUFTS COLLEGE STUDIES, VOL. II, No. 3 



including forms which, before the intermediate gradations had 

 been seen, passed without question as distinct species. Four 

 varieties are recognized by Mme. Weber, of which we have 

 three, all occurring at Guadeloupe. 



Var. TYPICA Weber, 1898, p. 312. Frond usually spirally 

 twisted, frequently narrowed and dilated, margin dentate, teeth 

 as long as or longer than their width. 



Forma ANGUSTA Weber, 1898, p. 313. Frond narrow, the 

 interior margin of the spiral entire, the outer dentate ; constric- 

 tions few. 



Forma LATA Weber, 1898, p. 313. Frond broader; both 

 margins dentate ; constrictions frequent. 



Var. DE BORYANA (Ag.) Weber, 1898, p. 315. Frond sim- 

 ple, cylindrical or compressed, for a long distance before fork- 

 ing ; then plane, little or not at all twisted, dentate; teeth 

 distant. 



Forma OCCIDENTALIS Weber, 1898, p. 315. Frond not 

 twisted, teeth small, usually wider than long. The typical 

 variety de Boryana occurs in the Red Sea ; the forma occiden- 

 talis at Guadeloupe only. 



Var. PECTINATA (Maze and Schramm) Weber, 1898, p. 316; 

 Vickers, 1908, p. 28, PI. XLJVc. Frond very rarely twisted ; 

 constrictions few or many ; proliferations often frequent ; margin 

 of foliaceous part dentate or pectinate ; constrictions naked. 

 W. I. 



12. C. CUPRESSOIDES (Vahl) Agardh, 1822, p. 441 ; Weber, 

 1898, p. 323, Pis. XVII and XVIII ; Harvey, 1858, p. 21, PI. 

 XXXIX. B; Alg. Am.-Bor., No. 96 ; P. B.-A., Nos. 79, 575, 

 765. Stolon usually stout, naked ; branches of frond dichoto- 

 mous, fastigiate or irregular, surrounded by ramuli ; ramuli 

 distichous, tristichous, or multiseriate, " sub-navicular " in 

 form, with broad base at the central axis and rounded dorsally ; 

 other ramuli ovoid, conical, compressed, or even cylindrical ; 

 always mucronate. Literal to 30 m. depth. Fla., W. I. 



An extremely variable species, including many species of 

 earlier authors, species apparently distinct in themselves, but 

 now found to be connected by every gradation. The varieties 

 given below indicate mostly the typical forms of these supposed 

 species, and must be considered merely as showing the range of 

 variation. The best test for the species as a whole is the pres- 

 ence of the "sub-navicular" or " rostriform " ramuli. Kven 



