trds the side, the middle of the upper margin of the frond being often eroded or becoming 



mort leeply cleft. They are distinctly zonate. The frond filaments (fig. 100) are often 



I with dense brownish-yellow tents, but again often are pallid and contain granules 



A common feature at the base of dichotomia] branches is the pre ence <>f a slight 



swellinj pallid. immediately above the basal constriction. 



plants in question differ from / sordida in structure, that is in being composed 

 of filaments having a fairly uniform si/e, slightly larger than thal of the thickest filaments of 



usually more deeply coloured, more uniform!) « \ linclrical and du not 



lown to Ier terminal ramuli (6 p in diameter). They exhibit some points of resem- 



figure of his Rhipilia longicaulis (Tab. Phyc. VIII. 1858. p. 13, tab. 



11 . to wit. tin- upright rhizome with one or more thickenings or scars of lallen fronds, 



t frond, though in . /. Elliottii the frond is not obovate l>ut semiorbicular, 



and twice as wide as Kt rziNG's hond. But as regards the filaments, if the accnracy of KüTZING's 



drawing and magnifications can be depended upon, the filaments of R. longicaulis Kut/, taper 



from about 25 •>. at the coloured torulose part down to 5 y. at their colourless apices. In ./. 



Elliottii on the other hand, the filaments scarcely tapcr at all, being rarely less than 20^. at 



the apices and measuring 25 — 30 a elsewhere. Further remarks about Rhipilia longicaulis Kütz. 



are eriven under ./. Mazei and ./. sordida. 



&' 



10. Avrainvillea Gardineri A. & E. S. Gepp 



in Trans. Linn. Soc. (Hot.) VII 190S p. 179; pi. 24, figs. 23, 24; (Zool.) XII. 1909 p. 389, 

 pi. : 23, 24. 



I/al'. INDIC. Cargados Carajos, 22 — 47 fathoms, J. Stanley Gardineri 



Plant large, attaining a height of over 30 cm., solitary, consisting of a stout lurid-brownish 

 rhizome, 9 — 12 cm. long, 1.5 cm. thick, ascending somewhat obliquely from a bulbous base, 

 and suddenly transformed at its apex into a short flattened green stipes, 1.5 — 2.5 cm. long, 

 6 — 9 mm. wide, which bears the frond. Frond very large, dark olive to lighter green, not 

 brown, up to iS cm. long, 20 cm. wide, rotundate, at base usually cordate or auriculate-cordate, 

 membranaceous, zoned, margin entire in young plants, coarsely laccrate in large plants. Filaments 

 ot frond laxly interwoven and easily teased apart, 20 — 30 u in width, not tapering to apices, 

 tor the most part regularly torulose; apices slightly tortuous, free, not interwoven [Figs. 101, 102]. 



species was recently obtained from deep water in the western part of the Indian 



n by Mr. Gardiner during the "Sealark" Fxpedition. It attains large dimensions (fig. 101 



alf natur; comparable with those recorded for the West Indian species, . /. nigricans 



markable for its long sub-erect rhizome, which gives the plant the appearance 



stalk : luit the actual stipes which bears the frond rarely reaches a length of 



stipes is terminal, i. e. continuous with the rhizome, but distinguished from it by 



smaller diameter and flatter shape. The impression one gets from the plant 



rows immersed in mud and the stipes and frond stand out in the clear 



thin and when held up to the light reveals the zonate markings 



