78 BOTANICAL RESULTS OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 



17. GELIDIUM CORNEUM, Lam. Two specimens without fruit. Also two fragments 

 attached to Sargassum vulgare. St Vincent, December 1, 1902. Shore. 



Geographical Distribution. Cosmopolitan. 

 ^ 



18. CALLOPHYLLIS VARIEGATA, Kiltz. ? Scotia Bay, South Orkneys, July 1903. 



Geographical Distribution. S.-E. Pacific, New Guinea, Kerguelen, Auckland 

 Islands, and Straits of Magellan. 



This is a sterile and incomplete plant, and consequently we are unable to determine 

 it with certainty. Its structure, as seen in a transverse section of an older part of the 

 frond, much resembles that of Callophyllis variegata. The thallus is composed of two 

 strata, the interior consisting of large, thick-walled cells, separated from one another by 

 smaller flexuose tubular cells, and passing into a cortex of small round cells, laxly and 

 irregularly arranged in a cartilaginous matrix. The cortex is here and there invaded by 

 a green endophyte, probably Chlorochytrium (fig. 8). In younger parts of the frond the 

 cortex is monostromatic, and the interior has a fibrous appearance, owing to the collapse 

 of the cells. As to the habit of the plant, the base is absent, and the fragment of 

 thallus which we have seen is more or less palmately lobate and irregularly proliferous, 

 membranaceous in texture, and coccineo-rosaceous in colour. The specimen is 7 cm. 

 high and 9 cm. wide. 



C. variegata is of common occurrence about Cape Horn and the Falkland Islands, 

 and our plant may be one of its broader forms. 



19. ACANTHOCOCCUS SPiNULiGER, Hook, and Harv. Scotia Bay, South Orkneys, 

 9-10 fathoms, May 1903 ; December 1903. 



Geographical Distribution. Cape Horn, Falklands, Punta Arenas. 



20. GRACILARIA SIMPLEX, A. and E. S. Gepp inJourn. of Bot., xliii., 1905, p. 195, 

 tab. 472, fig. 4 ; National Antarctic Expedition, iii., British Museum (Natural 

 History), 1907, Marine Algae, pp. 9, 10. 



Syn. Leptosarca simplex, A. and E. S. Gepp in Journ. of Bot., xliii., 1905, 

 pp. 108, 162, tab. 470, figs. 10, 11. 



Frondes plures (8-10) e callo minuto ortae simplices oblongse vel lato-cuneatoe planse 

 membranaceae, 10-15 cm. longae (apice destructo), 3-8 cm. latse, c. 230 M crassse, inferne 

 in stipitem plus minusve sensim angustatum, 1-3 cm. longum attenuatse, stratis duobus 

 contextse, cellulis interioribus rotundato-angulatis magnis 2-3-seriatis pachydermis 

 (frondis sterilis majoribus maxime leptodermis collabentibus submonostromaticis) ; 

 cellulis corticalibus filamenta ramosa verticalia efficientibus, tetrasporangia magna cruci- 

 atim divisa foventibus (frondis sterilis majoribus monostromaticis). (Figs. 9-11.) 



Habitat. South Orkneys, shores of Uruguay Cove, March 26, 1903 ; also Scotia 

 Bay, June 1903. This species was also collected by the British, French, and Swedish 

 Antarctic Expeditions. 



When first studying this species we had but a few sterile fronds before us ; and, 

 noting the extreme thinness of frond, the large celled monostromatic cortex, and the 



