610 DEEBESIACEAE. 



Cay, Mariguana, Calcos Islands, and Great Eagged Island : — ^Bermuda and Florida 

 to South America ; Indian and Pacific Oceans. Type from St. Croix, American 

 Virgin Islands. 



Variable in the number of ranks of the ramuli and in the length of the ramull. 

 The forms or varieties chiefly represented are the typical form, the var. ericifolia 

 (Turn.) Web.-Y. Bosse, and the var. Lycopodium (J, Ag.) Web. -v. Bosse. 



10. Caulerpa racemosa (Forsk.) J. Ag. Till Alg. Sjst. 1: 35. 1S73. 



Fucus raeemosus Porsk. M. Aegypt.-Arab. 191. 1775. 



Fueus uvifer Turn. Hist. Fuo. 4: 81. pi. S30. 1819. Not Fucus uvifer 



Forsk. M. Aegypt.-Arab. 192. 1775. 



Caulerpa clavifera uvifera Ag. Sp. Alg. 1 : 438. 1822. 



On reefs in shallow water and in more sheltered places, as on roots of BMzo- 

 phora. New Providence, Eose Island, Bimini, Exuma Chain, Watling's Island, At- 

 wood Cay, and Castle Island : — ^Bermuda and Florida to Barbados ; widely distributed 

 in tropical and subtropical seas. Type probably from the Eed Sea. 



11. Caulerpa clavifera (Turn.) Ag. Sp. Alg. 1: 438. 1822. 



Fucus clavifer Turn. Hist. Fuc. 1: 126. pi. 57. 1808. 



Caulerpa racemosa clavifera "Web.-v. Bosse, Ann. Jard. Bot. Buitenzorg 



15: 360. pi. 33. f. 1-5. 1S98. 

 Caulerpa racemosa uvifera Web.-v. Bosse, loc. cit. 362 p.p. 



Habitat same as C. racemosa. Exuma Chain, South Cat Cay, Mariguana, 

 Caicos Islands, and Great Eagged Island : — Florida to Barbados ; widely' dis- 

 tributed in tropical and subtropical seas. Type from the Eed Sea. 



Caulerpa racemosa and C clavifera sometimes approach each other in form 

 and habit and rarely occurring specimens are difllcult to determine, but the writer 

 has often seen the two growing close together, in apparently identical surroundings 

 (especially in Porto Rico and Jamaica) and maintaining their distinctions so per- 

 fectly and strikingly that it seems more satisfactory to treat them as independent 

 species than to follow the prevailing modern fashion of regarding them as forms 

 of a single polymorphous species. 



Family 11. DERBESIACEAE. 



1. DEBBESIA Solier, Ann. Sci. Nat. Bot. III. 7: 158. 1847. 

 1. Derbesia vaucheriaef ormis (Harv.) J. Ag. Till Alg. Syst. 5 : 34. 1887. 



Chlorodesmis (?) vaucheriaeformis Harv. Ner. Bor.-Am. 3: 30. pi. 40 D. 



18&8. 

 Deriesia tenwissima Farl. Mar. Alg. N. E. 60 p.p. pi. 4. f. 4. 1881. Not 



D. tenuissima (De Not.) Crouan. 



On rocks in a salt spring, high littoral, Cave Cays, Exuma Chain : — southern 

 Massachusetts, Bermuda, and Florida. Type from Key West, Florida. 



The only Bahamian collection seems to be sterile, like Harvey's original ; its 

 filaments are somewhat coarser, being 35-&3 u, in diameter, while those of the type 

 are 30-52 /i ; the plants are also much darker green than Harvey's specimens at the 

 present day, but the latter have doubtless suffered some loss of color in nearly 

 seventy years of preservation. 



2. BE.YOBBSIA Web.-v. Bosse, Ann. Jard. Bot. Buitenzorg 24: 26. 1910. 

 1. Eryobesia cylindroc4rpa sp. nov. 



Filaments sparingly subdichotomous, 5-15 mm. long, 75-156 n in diameter, 

 very rarely septate, their walls mostly 3-10 /j, thick, the branches occasionally 

 with a septum at the base ; sporangia short-eylindric, obovoid, or cylindric-clavate, 

 150-450 n X 9'0-lSO |U, sessile, erect or erecto-patent, constituting one arm of a 



