PLATE 



a 11. sp. Pilaments of frond from bas. il margin, showing truncate papillae, which, like 

 the appendages of U. palmetta and of U. spinulosa, occur only on the exposed side of the 

 filaments. The supra-dichotomial constrictions are very uneven and, in nature, are much more 

 strongly constricted than as represented in the figure; a and /> 83; c 178. 



14. U. indica. Filaments of stipes, shewing lateral appendages, 83. 



15. U. argentea Zan. var. spumosa nov. var. Part of largc plant, nat. size. (Saleyer, reef. Siboga 



1 xpedition). 



1 16. U. verticillosa A. & E. S. Gepp. llabit of plant, nat. size. (St. Thomas, West Indies, B Challen 

 Expedition, 5 — 15 fathoms). 



I 17. ('. papillosa n. sp. Smal! plants, or, strictly speaking, proliferations broken off from a larger 



plant, nat. size, iSil)'>_;a Expedition). 

 18. '*. occidentalis n. sp. Surface view of frond, before decalcification, showing the sinuous lines of 

 demarcation between the contiguous inflated capitula of the lateral appendages, which are 

 borne on the filaments of the frond and form a cortical covering of the frond. In each of 

 the sinuous areas I are seen three or more of the "windows" described in the text. 



472. \\\st [ndies, St. Thomas, " CAallenger" Expedition, in Herb. Mus. Rrit.). 



Fig. 19. U. verticillosa. Surface view of frond, before decalcification, shewing encrusted spinose fila- 

 ment^. 20. 



I 20. U. papillosa n. sp. Surface view of frond, before decalcification, seen by surface illumination. 



ii. near upper margin ; /'. near base, 70. 



i Si. U. argentea Zan. I'ortion of frond after decalcification, showing main filaments bearing lateral 



appendages (for comparison with the lost type-specimen from Suez, figured by ZaNARDINI in 

 his Plant. mar. rubr. coll. tab. XII. fig. ló), 83. 



Fig. 22,1 and /'. U. occidentalis. n. Filaments of frond, shewing lateral appendages of nearly equal length, 

 with pluri-lobulate inflated capitula. 83. b. Two of these lateral appendages shewing stalk 

 expanding above obconically, and dividing into two or more embossed inflated lobules, each 

 bearing some six <>f the "windows" described in the text. 472. 

 22c. U. argentea f. typica; part verging towards var. spumosa. <\ Filament of frond, showing lateral 

 appendages with stalked, longly obconic capitula, rounded, flattened, or depressed at apex. 

 simple or occasionally lobed. Other filaments of the same plant bear the lobate and embossed 

 lateral appendages off. typn a. 1 Karkaralong, Siboga Expedition) 83. (Fig. 22,/ is on plate III]. 



