13 1 



Ar.ilu.ui G Red Sea which i ■ •■ '■''■ Phyc. VIII 1858 tab. 27 under the 



narne /. 1 and which we discuss under U. explanaia (p. 121 



( ,, we know, confined to the western Indian Ocean 



I lowe 



i„ ï I 1 Club XXXVI. 1909 p. 97, pi. IV. fig. 2; pi. VIII, figs. 1 -7. 



1 ollin Gn Vlg N. Amer. in Tufts College Studies II 



. Collected on a sandy bottom mar low-watei mark in Bemini Harbor, Bahamas, 

 April 17, 1 

 sine loco sub nomine " ('. conglutinata' Chauvin MS. in Herb. dun'. - St. Jan. Danish 

 West Indies, B'órgesen n" 1915 pro parte and n" 2101 pro par St. Thomas, 5 1; 



fathoms, *Challenger" Expedition, in Herb. Keu! 



■Plants 7 8 cm. high, from a fusiform or fasciculate-funicular rhizoidal base, grayish 

 en, strongl) calcified; stipe simple, subterete below, flattened above, 1 2 cm. long, 

 *3 — 4 mm. wide, corticated, its surface nearly smooth or minutely velutinous-tomentulose : 

 'flabellum obovate with a subcuneate base, 5 — 6 cm. long, 1 -6 cm. wide, 0.4 — 0.6 mm. thick, 

 'longitudinally furrowed or striate, not at all or very faintly zonate, rather rigid and brittle 

 "when dry, lateral margins subentire, apical margin more or less laciniate and commonly 

 ■fractured, the surface appearing minutely corrugated or spongiose-velutinous under a lens, 

 "becoming compact and nearly smooth toward the base: filaments of the flabellum in 3 — 7 

 "layers, nearly |>arallel or flexuose and interwoven, subcylindrical, sparingly dichotomous, 

 "stronglj constricted just above the dichotomies, 4') -84 •>. in diameter, enclosed in a non-porose 

 "calcarcous sheath especially in the outer parts, or irregularly incrusted, the superficial (or the 

 "interior wherever they touch the surface) thickly beset externally with short cylindrical, trun- 

 "cate-conical, subturbinate or obconical processes- 16 — 407. in diameter, each crowned with 

 "2 — S acuminate prongs or spines formeel l>v 1 — 3 close-set dichotomies, these lateral processes' 

 ■(mostly 55 — 160 ju, long, including their spinulose crowns) forming an imperfect kind ol cortex; 

 "medullary filaments of the stipe 70 — MOa in diameter, the lateral corticating branches 4 — 6 

 "times dichotomous, their ultimate divisions taper-pointed, 28 — 200 ju. long and S — 24 7. in 

 "metlian diameter". [Figs. 12, 55]. 



We give I )r. Howe's full description as published. The plant described and figured by 

 I )r Howe is unmistakeable (our lig. 55). We found a specimen of it seven years ago among 

 ' \ in's algae preserved in the Caen Herbarium. That specimen is without locality, like 

 U. palmetta, and lias always been a mystery to us. There can be but little doubt 

 now that Chaüvin's plant came from the West Indies and probably from the Bahamas, like 

 others of his calcified algae 



U. spinulosa differs from its nearesl ally, U. palmetta, an Indian Ocean species, as 



•iis out, "in the thicker (0.4 0.6 vs. d.09 — o. 16 mm.), more rigid, less zonate 



■•Hum and its subcuneate base, by the larger (46 84 u. vs. S — .;<>;/). less flattened fila- 



ilarly and strongly constricted above the dichotomies, and by the character 



