1 1 



In n the other hand the stipes is nol branched, the frond therefore is 



m witli cordate ba 



iomewhal resemble in habit crowded compacl plants 



haracterised by having their principal filaments of the 



form. In both species these measure about 25 p 'm the 



of ./. lacerata diminish in size to .1 diameter of 6 u al their 



'. amadelpha which possess a good pseudo corte . usuallj measure 



■ vit in some plants ol A. amadelpha, having a poorl) developed 



sometimes diminish to 6 p at their apices, In such cases ii is 



lish the two species, but for the fact thal the ultimate branchlets of the 



(rond i"i' /■ amadelpha are usually torulose to a greater degree and along a greater 



tortuous and are often, so i<> speak, unilaterally torulo 



phical distribution is also a help. A. amadelpha is confined to the western Indian 

 n from which we have as yet rio authentic record of A. lacerata. It is truc that 

 Zanardini's Chloroplegma sordidum of the Red Sea has been commonly referred i<> ./. lacerata 

 /eral authors; Kut th.it is because thej did not realise the identity of A. amadelpha. 



15. Avrainvillea asarifolia Börgesen 



in Vid. Mcckl. Nat. For. Kjöbnhavn ïyoS. p. 34, fig. 4, and tab. lil. 



Hab. Atlantic. West Indies: St. Thomas, off Water Island, depth 20 meters, /•'. Börgesen. — 

 St. Jan. <>it' Christiansfort, depth 30 meters, and near the isle of Gt. St. James, 30 meters, 

 /•'. Börgesen. 



Dark-olive-green or sometimes greyish when dried; mosl probably of a similar colour 

 when living; rhizome terete; stipes cylindric in the lower part. more flattened higher tip, 

 ■11. long, about 7 mm. in diameter. 



Flabellum oblong-reniform with cordate or cuneate base up to about 10 cm. high and 



m. broad, entire or lobed, thin and membranous, rather firm, tor the most part zonate. 



Filaments in the interior of the flabellum cylindric or often slightly moniliform or torulose 



with a rather strong constriction just above the dichotomy. The diameter of the filaments about 



;. more often reaching only 24 2- ■>.. Near the surface the filaments grow gradually 



oming more and more torulose and more richly ramified, woven together, forming 



rather firm but yet open plectenchyma ; the diameter of the outermost filaments varies from 



and their walls are rather thick, thicker tlian those of the filaments in the middle 



lum. Sometimes the apex of a filament runs out into a long hair. [Figs. 110, 117]. 



;i"M. is extracted with slight alteration from Dr. Börgi si \\ account ol 



npan 5 it with . /. sordida \.\. levis Howe), as follows: — 



with ./.-/-. levis Howe, of which 1 possess an original specimen kindly sent 



mj species differs, besides its largeness, by having the filaments of the 



lo e than in Avr. levis where the outermost filaments run out in long, 



"thin, bij torulose threads". 



