WEBER-VAN BOSSE—MARINE ALGAE 279 
Seychelles, Long Island. 
Distribution. Red Sea; Indian Ocean. 
Evucueuma, J. Agardh. 
1. EvcHrumaA Corrontt, n. sp. (Plate 16. fig. 2.) 
Thallo crasso, carnoso, depresso, decumbente, lateraliter et subdichotomice ramoso, 
latere superiore verrucis et tuberculis aggregatis, latere inferiore tuberculis remoti- 
oribus obsito. Verrucis nonnunquam forma irregulari; tuberculis vulgo parvis et 
rotundis, nonnunquam apiculatis. Regione mediana thalli ad apices e cellulis satis 
magnis hyphis circumdatis constante, hyphis infra item auctis et cellulas satis 
magnas formantibus; peripheriam versus cellulis diminutis et ibidem series breves 
formantibus. Organis fructificationis ignotis. 
Saya de Malha, 25 fms. ; in alcohol. 
Cargados Carajos, 26 fms.; dry specimen. 
#. Oottonii is unfortunately a barren plant, and shows, in a dry state, a great likeness 
to species of Gracilaria. I moistened it, to restore as much as possible its natural 
appearance, and was then struck by its great resemblance to Hucheuma. 'The figures 
are made from these moistened specimens, and show well the horizontally spread, 
laterally branched thallus, covered with warts and more or less pointed tubercles. 
The anatomical structure at the apex is also entirely different from that of Gracilaria, 
though, in a cross-section at some distance from the apex, only round, rather large, and 
somewhat thick-walled cells are to be seen. But these cells are of different origin from 
the primary large cells, for at the apex the latter are seen to be surrounded by narrow 
hyphee, which grow out lower down into large cells and are then no longer discernible 
as hyphe. 
The genus Hucheuma is described by Schmitz in Engler u. Prantl, ‘‘ Pllanzen-Familien,” 
as having a central axis of slender elongated hyphe. ‘This axis is found, for instance, 
in EF. spinosum. Agardh has, however, called attention to the fact that LH. Schrammi 
has a structure in which “fila strati interioris sparsim inter cellulas strati intermedii 
quasi introducta obveniunt.” Schmitz, again, supposes that EL. Schrammi, Crouan, is 
not an Hucheuma but an Huryomma. 
My studies on the Hucheumata of the Malay Archipelago seem to indicate that there 
are species of Hucheuma without a central axis of longitudinal hyphe. The investi- 
gations are not complete, but it appears to me not improbable that the cylindrical erect 
species have an axis of narrow cells, and that in the flat prostrate species this is absent. 
I did not find an axis in any prostrate specimens of Huchewma of which I was able to 
study the cystocarp. The whole question needs to be further investigated, but for 
the present it seems highly probable that the algze from Saya de Malha and Cargados 
Carajos belong to the genus Hucheuma, and the name I propose for it is in kind 
remembrance of Mr. Cotton’s friendly help. 
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