Zoohgy.1 NATURAL HISTORY OF VICTORIA. [Poli/zoa. 



very wide and covered liy a tliiu membrane, is another similar 

 closed compartment extending almost to tlie base of the cell. This 

 gives to the cell a peculiar hexagonal or rhomboidal figure, which, 

 ■with the constant three foramina, at once cUstinguishes this fi'om 

 the other species. The ovicell is of large size, surmomited by a 

 single avicularinm. 



Explanation of Figukes. 



Plate 24.— ri?. 8, natural size. Fig. 8a, front view of cells, with ovicell, magnified. 

 Fig. 86, back of cells, magnified. 



Plate 24, Fia. 9. 

 CATENICELLA FORIMOSA (Busk). 



Description. — Cells pyriform or subglolmlar; in front covered with numerous 

 papilla?; a broadly linear or ellijitical vitta extends up each side. Lateral processes 

 larg'e, straig-ht or nearlj' so above, jirodiiced downward.*! as a narrow f'ring-e, a round 

 perforation at the base of each. Avicularia small, lodged in shallow excavations. 

 Back of cell smooth. 



Refekence.— Busk, Voy. Ratt., i., 3G0 ; Cat. Mar. Pol. Brit. Mus., t. 7, f. 1, 2. 



QueensclifF, Cape Schanck, Eivoli Bay, and other places. 



This, the largest as yet known of the vittate di-\nsion, forms 

 handsome dusky-brown tufts. The cells are broadly pyriform or 

 subglobose. The front is covered mth minute, pointed, papillEe, 

 and has, on cither side, a broad vitta, extending fi-om the base to 

 nearly the level of the lower lip. The lateral processes are large, 

 straight above, generally projecting a little upwards, and produced 

 interiorly into a nari'ow fringe usually running to the base of the 

 cells ; on each process there is at the base nearly opposite the 

 lower lip a constant round opening ; the avicularinm is of small 

 size, and lodged in a shallow excavation in the edge of the lateral 

 process. 



Explanation of Figures. 



Plate 24. — Fig. 9, natural size. Fig. 9«, front view of cells, magnified. Fig. 96, back 

 view of cells, magnified. 



[22] 



