THE AL<;.K OF < OMMONWEALTH BAY LI I \S. L5 



The fronds variedin length from 7 cm. to 18 cm. Unfortunately, all were sterile. 

 The growth of the frond follows the growth of the branching axis. The main " costa " 

 may persist to the extremity of the frond, giving ou1 opposite, or approximately 

 opposite, "veins" a1 distances which increase as the pari of the frond grows older. 

 As growth proceeds, costa and veins increase in Length in a somewhal sinuous course, 

 the lamina not keeping pace with them. Tims the frond becomes lobed and takes 

 on the oak-leaf form. The veins give out secondary veins in the same way. At certain 

 piaiits on the primary veins the lamina may be so much reduced, or be actually denuded, 

 so that the lobe becomes a pinna. The genera] outline of a young frond or young pinna 

 is roughly oval. Then appear in order of growth sinuations, lobes, pinnae or pinnulse. 

 Thus the originally simple frond may become bi- or tri-pirmate. The lamina oi the 

 main axis becomes denuded at the base with age, and thus an apparent stipes appears. 



Occasionally the main costa forks, and forms two equal branches, which develop 

 in the normal manner. (Plate 8, ngs. 1, 2.) 



Distribution. — North Pacific, Falkland [., Cap.' Horn, tie Petermann (*' Pourquoi 



Pas?"), Hermite I., Kerguelen, off Cape Wads worth, Coulmein I. (" Discovery ""). 



Ceramiace.e ( Bonnemaison ) Naegeli. 



Bornef.ia Thuret . 



Bornetia (?) antarctica (Honker and Harvey) De Toni = Griffithsia antartica Hooker 



aaid Harvey. 



A single incomplete sterile filament was preserved which seems to belong to this 

 species. 



It measured 5 cm. in length, and consisted in a chain of almost cylindrical cells, 

 tapering at each end to the narrow constriction between the articuli. Each articulus 

 was about 2 mm. Long and -4.") mm. wide, the dividing septa about -1 1 mm. wide. This 

 agrees with the description given by De Toni. Sylloge IV. p. 1l".»7. though the material 

 is too meagre to enable me to speak with certainty. 



Distribution of Griffithsia antarctica as given by De Toni :- Pocks at Cape Horn, 

 Hermite, Kerguelen, and Falkland Islands. Doubtfully identical the plants from 

 Tasmania and New Zea.la.nd. 



Hull in Harvey. 



Ballia callitricha (Agardh) Montagne. 



Sparingly represented by worn fragments. One small fragment was present in 

 the haul obtained by the dredge in 45 50 tat horns. 



