125 



"of their lateral appendages, which are closely i — 3 times dichotomous instead of simple or 

 "once furcate and are 55 — ióoy. long instead of 11 — 30 ( u long, the spines crowning a thick 

 "stump-like base or pedestal instead of being practically sessile." 



There is however a form in which the lateral appendages of the frond-filaments are 

 very weakly developed, being much reduced in size, and disappearing altogether in the apical 

 part of the filament; that is to say, the topmost 2 — 3 mm. of the filaments are entirely 

 destitute of lateral appendages. For this form we propose the name 



forma palmcttoidea. 



Syn. Udotea conglutinata Dickie in Journ. Linn. Soc. (Bot.) XIV. 1875. p. 312, pro parte. 



Hab. ATLANTIC. St. Thomas 5 — 15 fathoms, "Chat/enger" Expedition in Herb. Kevv! 



Filaments of the frond bearing lateral appendages arranged secundly as in the type, 



but smaller (10 u. long), simple to trifid, and sessile above ; below 2 — 3-fid, sometimes simple, 



40 — 70 (sometimes up to 110) u. long, pedicellate-, all acute; absent from the topmost 2 — 3 mm. 

 of the filament. (Fig. 56]. 



The type in Kew Herbarium bears in Dickie's MS. the name " Udotea conglutinata' and 

 was published as such by him. It is the larger of two plants stuck on the same mount, the 

 other plant being a specimen of our U. verticillosa. 



Though f. palmcttoidea differs much from the type of U. spinulosa in the weak deve- 

 lopment of its lateral appendages, it must not be confused with U. paliuetfa, an Indian Ocean 

 species, which at first sight it broadly resembles. It is easily distinguished at once by its 

 even supra-dichotomial constrictions (fig. 56), and by its 2 — 3-fid pedicellate lateral appendages. 

 The supra-dichotomial constrictions of U. palmetta are uneven (as is the case in almost all 

 East Indian species of Udotea) and the lateral appendages are simple or bifid (rarely trifid) 

 and sessile (rarely shortly pedicellate). 



Dr. Börgesen collected in St. Jan (11" 2101 pro parte) a plant intermediate between 

 the type and the f. pahncttoidca. 



The differences which distinguish U. verticillosa from U. spinulosa are given under the 

 former species (p. 129). 



The geographical distribution of U. spinulosa is confined to the Bahamas and the 

 Danish West Indies. 



1 1 . Udotea argentea Zanardini 



in Plant. Mar. Rubr. in Mem. R. Ist. Ven. vol. VII. 1858. p. 290. tab. X, figs. 1, ia, 1 b. 

 Syn. Udotea ar genten J. G. Agardh Till Alg. Syst. V. 1889. p. 76. 

 Udotea argentea De Toni Syll. Algarum I. 1889. p. 511. 



Udotea argentea A. & E. S. Gepp in Trans. Linn. Soc. (Bot.) VII. 1908. p. 176; also op. cit. 

 (Zool.) XII. 1909. p. 386. 



forma typica : 



Hab. INDIC. Red Sea, Suez, Portier. — Suez Bay, Crossla/id'. -- Seychelles, Coetivy reef, J. Stanley 

 Gardinerl — Cargados Carajos, 22, 30, and 47 fathoms, J. Stanley Gardiner\ 



