37 



very clearly. When young and small it is quite entire, but in old plants it is often deeply and 

 flabellately lacerate. In colour the frond varies from a deep olive to a lighter green, while 

 the rhizome is pale brown. The shape of the frond is rather cuneate in young plants and in 

 older ones it is often auriculate-cordate. 



The filaments of the frond are markedly torulose (fig. 102) for some distance behind 

 the apex and do not taper towards their apices. These are often tortuous but not markedly 

 interwoven. 



The nearest all}- of A. Gardineri in structure is A. pacifica (infra), which it resembles 

 in the torulose character of the filaments and to a certain extent in their diameter ; but the 

 habit of the two species is quite different, as also their geographical distribution. A. Gardineri 

 bears one thin large solitary frond, arising from a long rhizome, while A. pacifica bears two or 

 even more comparatively small fronds arising from a short thick ba^e. The filaments of A. 

 pacifica vary in diameter to a greater extent (25 — 6 u.) than those of A. Gardineri (30 — 20 fjt.). 



A. Gardineri resembles A. nigricans Decne. in having torulose filaments, but differs 

 greatly in the diameter of the filaments, those of A. nigricans measuring 60 u. or more inside 

 the frond, diminishing to 30 u. at their apices. Moreover A. nigricans is a West Indian species, 

 while A. Gardineri is as yet known only from Cargados Carajos in the western Indian Ocean. 

 This region is also the home of A. amadclpha, which however has a wider local distribution, 

 and differs from A. Gardineri in habit and structure. A. amadelpha consists of from two to 

 many fronds arising from a common base, and is characterised by smaller and tapering frond 

 filaments, which usually form a pseudo-cortex upon the surface of the frond. 



11. Avrainvillea pacifica n. sp. 



Hab. PACIFIC. Ellice Isles: Fualopa, A.14. Davidl Funafuti Expedition, 1898. — Paumotu Archi- 

 pelago: Otépa récif, 1904, L. G. Seuratl — Hikueru lagon, 1905, L. G. Seurat\ 



Plant brownish, consisting of 2 or more stipitate fronds arising from a thickened base ; 

 stipes short (up to 2.5 cm. long), stout (up to 1.25 cm. thick), bearing a cordato-semirotundate 

 frond, ezonate, margin entire, rather thick (not membranaceous). Frond 5.6 cm. long, S.i cm. 

 wide (in type). Filaments of frond thin, tapering in interior from 25 u. down to about 6 [x at 

 their apices, wide-angled at their dichotomies, longly and markedly torulose, colourless to 

 light-brown, apices often tortuous or hooked, not interwoven into a pseudo-cortex, but easily 

 teased asunder. [Figs. 103, 104]. 



The details of the above description were drawn from the Fualopa specimen (fig. 103) 

 which is preserved in alcohol in the British Museum. The other specimens, kindly sent to us 

 by Monsieur P. Hariot in April 1907, and referred by us at that time to A. lacerata, are 

 dried plants. One of them has four crowded fronds arising from the common base. All of them 

 have a thinner frond and more slender stem ; and the outline of the frond varies from cuneato- 

 flabellate to rotundate. The structure however is that of A. pacifica. 



A. pacifica belongs to the group of species which cluster round A. lacerata, being 

 allied with A. amadelpha, A. sordida Murr. & Bood. and A. asarifolia Borg. It resembles 



