MAI; INK \i.. 7 



It might IM; urged that L. <//vi///Y.'//</ and I.. .iinnl'in* arc sufficiently distinct 

 from LtMKHua to constitute a separate genus on account of the following characters : 

 The lamina- are huge and undergo no multiplication by longitudinal splitting, the stem 

 is poorly developed and exhibits no rings of secondary thickening, and no lacuna; are 

 present in lamina) and stem ; moreover, L. </rim///"// is markedly characterised I>y 

 the presence of numerous trumpct-hypha? in the medulla, as also is L. simiilniix to a 

 lesser extent. But though, at one time, we were tempted to separate these species from 

 Luaonia, we feel that such intermediate links as L. laininarioide* and L. oixitn are too 

 strong to admit of a generic separation, however great the contrast may be between our 

 plants and the typical dendroid species, L. fuscescen* and L. mgtUOHlt, 14x111 which 

 the genus was founded. Further, we would suggest that whereas L. fusceacenx and 

 L. <V//vce we evidently sturdy perennials, L. yrmuiifolia and L. ximulmix, with their 

 weak stems, may possibly be mere annual or biennial plants. Moreover, as mentioned 

 in the introduction, the local conditions of life in the Antarctic Ocean arc peculiar, and 

 though during the long winter night the growth of our two species may be inhibited, or 

 even replaced by decay, yet during the perpetual daylight of summer they may 

 possibly have a special capacity for rapid growth, and thus perhaps attain in one season 

 the huge dimensions of our specimens. If such be the case, we would suggest that the 

 trumpet-hypha), the actual function of which is unknown to us, may perhaps facilitate 

 rapid growth by providing channels for the ready transference of food-material and 

 waste products. That these trumpet-hyphse are connected in some way with the local 

 conditions of life seems evident from the abundant occurrence of similar ensheathcd 

 hyphaj in Desmarestia harveyana (figs. 14a, 13b), an Antarctic species which grows to a 

 considerable length. 



4. DKSMAKKSTIA HARVEYANA. 



(Plate III., figs. 11-15.) 

 Dttmartttta harityana, Gepp, Journal of Botany, 19<5, p. 106 (figi. 11-15). 



It. media Hook. f. et Harv. Flor. Antarct. II. (1847), p. 40C ; Kittling, Tab. Phjc. IX. (1*59), tab. 95, 



fig. II. ; hand Grev. Synop*. (1830), j>. XL. 

 D. ofiilfiln var. comprttta Reinach in Flora, 71 (I***), p. 190 ; et in Internat. Polarforsch. 1KX2-188S, 



iK-utach. Exped. Band II. (1890), p. 408, tab. XVII., fig. 3. 



Off Cape .Wads worth, Coalman Island, 18 fathoms ; Cape Adare, February 24, 1904. 



Geogr. Distrib. Cockburn Island. South Georgia. 



Specimens of this plant were preserved both dry and in formalin. One of the 

 latter is as much as G feet long, but being incomplete, must have been longer still when 

 growing. They agree absolutely with those from Cockburn Island, collected by D. Lyall 

 on Ross's Antarctic Expedition (1839-1842). Lyall's specimens in the British Museum 

 are named D. media in Harvey's MS. Harvey, indeed, was strongly of opinion that 

 they are identical with D. media Grev., i.e., Spvrochnus media* C.Ag., collected at 

 Unalaschka by Chamisso, and figured by C. Agwdh in his Icon, Alg. inn I., tab. 16 

 (1822). Although we have not seen Agardh's type, we arc so convinced that it is 



