266 



F. BORGESEN 



Zonaria Drapern. 



Z. variegata (Lamx.) Mert. — Fig. 14. 



Mertens in Martius, Icones plant, cryptog , p. 6, tab. 11, fig. 11. Richards, 

 H. M., Notes on Zonaria variegata Lamx. (Proc. of the Amer. Acad, of Arts and 

 Sciences, 1890). Sauvageau, C, Observations sur quelques Dictyot. et sur un 

 Aglaozonia nouveau (Bull, de la Station biol. d'Arcachon, 8 annee, 1904 — 05). 

 Borgesen, F., Marine Alg. D. W. I., vol. I, p. 197. — Dictyota variegata Lamx., 

 Essai, p. 57, tab. V, figs. 7 — 9. Gytnnosorus variegatus (Lamx.) J. Ag., Analecta 

 algol., cont. I, p. 11, 1894. 



The specimens collected agree very well with those from the West Indies. 

 They are 7 — 8 cm in diameter or even more; when dried they have a dark 

 nearly black-brown colour and their consistency is tough and rather stiff. 



m 





 



n 



^^E§§ 



Fig. 14. Zonaria variegata (Lamx.) Mert. a, b transverse sections, c. l75 /> : a radial, b tangential; 

 c upper surface of thallus, seen from above, c. 200 /i. 



The thallus is about 150 — 200 ;x thick. When examined from above the 

 epidermal cells are seen to be arranged very regularly in rows (Fig. 14 c). The 

 marginal rows consist of rather long rectangular cells, but these cells become 

 soon divided by longitudinal and transverse walls into smaller cells, each row 

 gradually getting composed of from two to four rows of small cells. These 

 cells have rounded corners and are filled with chromatophores. 



