BY W. A. HASWELL, M.A., B.SC. 37 



20. Scrupocellaria cervicornis, Busk. 

 A small scrap, seemingly of this species, from Holborn Island. 



21. Scrupocellaria diadema, Busk. 



22. Scrupocellaria Macandrei, Busk. 



23, Scrupocellaria clypeata, sp. nov., Plate I., fig. 6. 



Cells elongate, narrow, provided with a pedunculate operculum 

 which is long and narrow, extending much further in front of 

 the peduncle than behind, pointed in front, broader and truncate 

 behind; aperture ovate, margin prominent, armed above with 

 two small spines. 



24. Scrupocellaria obtecta, sj). nov. 



Cells provided with a large operculum covering the greater 

 part of the front of the cell, and occupied by a system of branching 

 canals of which the central one is much broader than the others. 

 A sessile avicularium on the inner side of the summit of each cell ; 

 no marginal spines. Ovicells punctate. 



Distinguished from S. cervicornis by the greater size of the 

 operculum and its attachment by a broad base, and the absence 

 of marginal spines. 



25. Halophila Johnstoniae, Gray. 

 26. Carbasea episcopalis, Busk. 



27. Carbasea cribriformis ? Busk. 



If the present species is identical with that described by Busk, 

 he can only have had under examination a small fragment, as he 

 makes no allusion to the very remarkable habit of the species, 

 beyond noticing the cribriform structure of the fronds. The frond 

 is wound spirally around an imaginar}^ axis, the breadth decreasing 

 in successive whorls ; the size of the whole structure is sometimes 

 very considerable. 



