594 DICTYOTACEAE. 



Sargassum pteropus Kiitz. Sp. Alg. 60S. 1849. 



Sargassum bahiense Kiitz. loc. cit. 



Sargassum trachyphyllum Kiitz. loc. cit. 609. 



Sargassum polyphyllvm Kiitz. loc. cit. Not S. polyphyllum J. Ag. Sp. 



Alg. 1: 308. 1848. 

 Carpacanthus polyceratius Kiitz. loc. cit. 624. 

 Carpacanthus spinulosus Kiitz. Tab. Phyc. 11: 15. pi. 46 f. II. 1861. 



At low-water mark and in shallow water. New Providence, Rose Island, Great 

 Bahama. North Cat Cay, Watling's Island, Caicos Islands, and Castle Island : West 

 Indies in general. Type from Cuba. 



The species, as here conceived, shows great variability in form, size, and texture 

 of the leaves, in the size and number of the cryptostomata, in smoothness or rough- 

 ness of the stem, and in the presence or absence of spines on the receptacles, but 

 specific segregations seem impossible. 



10. Sargassum Hystrix J. Ag. Of v. K. Vet.-Akad. Forh. 4: 7. 1847. 



Sargassum Hystrix buxifolium (Chauv.) J. Ag. Sp. Alg. 1: 322. 1848. 



Usually found floating or washed ashore, but also attached, in about 3 m. of 

 water. New Providence, Joulter's Cay, Abaco, Berry Islands, and Exuma Chain : 

 off North Carolina, Isle of Pines, and Mexico. Type from the Campeche Banks. 



A form with large oblong entire or subentire leaves is var. buxifolium. 



Family 7. DICTYOTACEAE. 

 1. ZONARIA Drap.; Ag. Syn. Alg. Scand. xx. 1817. 



Stypopodium Kiitz. Linnaea 17: 97. 1843. 

 Phycopteris Kiitz. loc. cit. 



Gymnosorus J. Ag. Anal. Alg. Cont. 1: 9. 1894. Not Gymnosorus Trevis. 

 Alg. Cocc. 108. 1848. 



Thallus obscurely zonate, brownish both when living and on drying, 2-7 cm. long, 

 at first more or less prostrate or subrepent and semiorbicular or fiabelliform, later 

 free except at the broad or occasionally substipitate base and 

 showing few entire or sparingly laciniate fiabelliform lobes. 1. Z. variegata. 



Thallus distinctly zonate, more or less brownish blue-green and 

 iridescent when living, commonly blackening oh drying, mostly 

 7-30 cm. long, erect, stipitate or substipitate. repeatedly cleft 

 or lobed, the lobes cuneate, cuneate-oblong, cuneate-flabelliform, 

 or linear, occasionally lacerate or fimbriate-laciniate. 2. Z. zonalis. 



1. Zonaria variegata (Lamour.) Ag. loc. cit. 



Dictyota variegata Lamour. Nouv. Bull. Sci. Soc. Philom. 1: 331. 1809. 



Zonaria collaris Ag. Sp. Alg. 127. 1820. 



Padina variegata Gaill. in Diet. Sci. Nat. 53: 371. 1828. 



Spatoglossum variegatum Kiitz. Sp. Alg. 560. 1849. 



Gymnosorus variegatus J. Ag. Anal. Alg. Cont. 1: 11. 1894. 



Gymnosorus collaris J. Ag. loc. cit. 



On calcareous algae, rocks, old corals, Gorgoniidae, roots of Rhizophora, shells 

 of conchs, etc., common from low-water mark down to a depth of several meters ; 

 often found washed ashore. New Providence, Rose Island. Andros, Berry Islands, 

 Great Bahama, Gun Cay, Abaco, Green Cay, Exuma Chain, Watling's Island, Atwood 

 Cay, Mariguana, Caicos Islands, and Great Ragged Island : Bermuda and Florida 

 to Brazil ; Canary Islands ; Philippines ; widely distributed in the warmer seas. 

 Type from the " Antilles." Prostrate or subrepent forms are to be distinguished 

 carefully from Aglaozonia canariensis. 



2. Zonaria zonalis (Lamour.) M. A. Howe, in Britton, Fl. Bermuda 507. 1918. 



Fucus zonalis Lamour. Diss. 38. pi. 25. f. 1. 1805. 



Dictyota zonata Lamour. Nouv. Bull. Sci. Soc. Philom. 1: 331. 1809. 



Zonaria lobata Ag. Syst. Alg. 265. 1824. 



Stypopodium lobatum Kiitz. Tab. Phyc. 9: 25. pi. 63. f. I. 1859. 



On rocks, etc., in shallow water, in moderately exposed positions. New Provi- 

 dence, Berry Islands, South Bimini, Gun Cay, Exuma Chain, and Atwood Cay ; 

 Bermuda to Brazil ; Canary Islands. Type from Santo Domingo. 



