576 KHODOMELACEAE. 



Dichotomous monosiphonous ramelli subverticillate and often 



subsquarrose, sometimes lightly corticated at base; main 



axes well corticated. 4. D. mollis. 



Monosiphonous ramelli spirally disposed, patent, divaricate, or 



subsquarrose, divaricately dichotomous. 



Main axes 0.250.75 mm. in diameter, corticated except in 



youngest parts; cystocarp subspheric-rostrate, 0.67-0.92 



mm. broad. 5. d. Collinsiana. 



Main axes 0.1-0.3 mm. in diameter, uncorticated or slightly 

 corticated near base; cystocarp conic-ovoid, about 0.2 

 mm. broad (immature). G. D. rigidula. 



1. Dasya pedicellata (Ag.) Ag. Syst. Alg. 211. 1824. 



Sphaerococcus pedicellatus Ag. Sp. Alg. 1: 321. 1822. 



RJiodonema elegans Martens, Eeise nach Venedig 2: 641. pi. 8. 1824. 



Dasya elegans Ag. Sp. Alg. 2: 117. 1828. 



Mostly in shallow water, New Providence, Berry Islands, and Great Bahama : 

 Massachusetts to Bermuda ; Florida ; and the northern West Indies ; Adriatic and 

 Mediterranean seas ; Canary Islands. Type from New York. 



The southern specimens are sometimes yellowish when living instead of the cus- 

 tomary lake-red. 



2. Dasya Crouaniana J. Ag. Till Alg. Syst. 6: 95. 1890. 



On surf-beaten rocks at low-water mark, Exuma Chain : Florida and Guade- 

 loupe. Type from Guadeloupe. 



3. Dasya ramosissima Harv. Ner. Bor.-Am. 2: 61. 1853. 



The verticils of sterile cells of the stiehidia are inclined to be protuberant 

 and they occasionally develop into few-celled simple or one-branched tricho- 

 phylls. In two observed cases the stichidium was forked near the apex. 



On roots of Rhizophora near low-water mark, Great Bahama : Florida. Type 

 from Key West, Florida. 



4. Dasya mollis Harv. Ner. Bor.-Am. 2: 62. 1853. 



On roots of Rhizophora, under shelving rocks, etc., near low-water mark, Exuma 

 Chain and Little Inagua : Florida and Cuba. Type from Key West, Florida. 



5. Dasya Collinsiana M. A. Howe, in Britton, Fl. Bermuda 524. 1918. 



The only specimen seen differs from the Bermudian type in being more 

 laxly branched, in being less manifestly dichotomo-eorymbose, in the more 

 "ocellate" congestion of the ramuli at the apices, and in the lighter cortica- 

 tion. It also bears cystocarps, hitherto undescribed for this species. These are 

 sessile, subspheric-rostrate, 670-920 [i broad, 600-750 /a high (without beak) 

 the beak being 350-500 /x long. In its cystocarps it seems to resemble D. 

 ramosissima, but the ramuli of D. Collinsiana are coarser and more divaricately 

 dichotomous and have a regularly spiral arrangement while those of D. ramosis- 

 sima are irregular or inclined to be subverticillate. 



In 2 meters of water, Great Bahama : Bermuda. Type from Bermuda. 



6. Dasya rigidula (Kiitz.) Ardiss. Florid. Ital. 2: 140. 1878. 



Eupogonium rigidulum Kiitz. Phyc. Gen. 415. 1843; Tab. Phyc. 14: pi. 85. 



f. c, d. 1864. 

 Eupogonium squarrosum Kiitz. Phyc. Gen. 415. 1843; Tab. Phyc. 14: pi. 



85. f. a, o. 1864. 

 Dasya squarrosa Zanard. Mem. 1st. Veneto 13: 163. pi. 53B. 1866. Not 



Dasya squarrosa Harv. in Hooker, J. D., Fl. New Zealand 2: 232. 1855. 



Much resembling Heterosiplionia Wurdemanni in size, habit, and micro- 

 scopic characters and easily confused with that species, but differing in its 

 radial instead of dorsiventral organization, in having its ramuli spirally dis- 



