MARINE PHANEROGAMS OF THE ' SEALARK’ EXPEDITION. 177 
Expedition, Madame Weber) and from Queensland (Bailey), the species exhibits slight 
modifications of internal structure ; and, further, a slightly modified form occurs in the 
West Indies. These forms we hope to describe in a paper soon to be published. 
CLADOCEPHALUS, Howe. 
27. CLADOCEPHALUS EXCENTRICUS, sp. n. (Plate 23. figs. 14-17.) 
Planta læte viridis, solitaria, usque ad 10 em. alta, adspectu primo Udoteam con- 
glutinatam simulans, stipite e substrato calcareo orto, simplici, olivaceo, usque ad 
3 cm. alta, tereti, solido, 1-2 mm. crasso; fronde inzequaliter cyathiformi, peltata, 
late expansa, primo rotundata, demum irregulariter elliptiea vel lobata, usque ad 
10 em. lata, membranacea, viridi, zonata; filamentis frondis primariis e stipite 
radiantibus, pallide viridibus, 25 4 crassis, superne in ramulos dense intertextos et 
corticem frondis formantes dichotome divisis, ramulis ultimis hyalinis 10 u crassis. 
Cargados Carajos, 30, 45, and 47 fms. 
The genus Cledocephalus was founded by Mr. M. A. Howe (Bull. Torrey Bot. Club, 
xxxii. 1905, p. 569) on a new plant, C. scoparius, collected by him in the Bahamas. 
The characters by which the author distinguishes this genus from Udotea, its nearest 
ally, are the external habit and the intricate labyrinthiform nature of the pseudo-cortex 
(figs. 15, 16), which is composed of repeatedly divaricato-dichotomous filaments closely 
interwoven. The author describes it thus:—“ The cortex is formed by branches 
originating subdichotomously from the more peripheral members of the medullary 
strand, and becoming afterwards apparently lateral. "These branches then undergo 
repeated divaricate forkings, with a gradual diminution of diameter, until finally they 
may have only one-fifth or even one-twelfth the diameter of the filaments of the central 
strand.” We find the same peculiar cortical structure in Flabellaria luteo-fusca, Crouan, 
from Guadeloupe; indeed a microscopical preparation of that species is quite indistin- 
guishable from one of Cladocephalus scoparius, Howe. The only difference between 
the two species is in the habit and colour. C. scoparius is of a yellowish-brown, 
substramineous, or olivaceous colour on drying and has a scopiform or thamnioid 
capitulum, “varying in outline from elongate-fusiform or elongate-ellipsoid to obovoid 
or subspherical,” while F. luteo-fusca has a cuneate-flabellate or spathulate frond, with 
à subentire to eroso-lacerate margin. The stem of F. luteo-fusca is sometimes branched, 
as is that of C. scoparius. | Cladocephalus being now established as an independent 
genus, F. /uteo-fusca, Crouan, must be transferred to it under the name of Cladocephalus 
luteo-fuscus *, 
Crouan's species was published by Mazé and Schramm (Algues de la Guadeloupe, 
ed. ii. 1870-77, p. 88) without description. They say :—“ Croit dans un fond de sable 
vaseux, entre des fragments de rochers et de madrépores brisés. . . . . Coloration brune 
noirâtre persistante. Saint Martin (Lac Simpson, pres lembareadére de lhabitation 
Durat, Anse du Marigot) Presque toute l'année. Coll. nos. 1403, 1904.” Consequently 
the Species could not be recognised save by comparison with an authentic specimen. 
gesen, having come to a similar conclusion 
* Since the present paper was read before the Society, Dr. F. Bor s 
about F, luteo-fusca, has transferred it to the genus Cladocephalus ( Vidensk. Meddel. naturh. Foren. Kjóbenhavn, 
1908, p. 44) 
