Zoology.] NATURAL HISTORY OF VICTORIA. [rolyzoa. 



both the exterior foramina are of much larger size, and usually 

 form a distinct series round the edge of the cell. Both have 

 frequently a semicircular area beneath the mouth more elevated 

 than the rest, and both are destitute of the upper appendage of 

 the lateral process. 



In C. cribraria the lower lip is entire, and there is a crescentic 

 pore a short distance beneath it ; the avicularia are lodged in deep 

 gaping excavations in the tolerably large lateral processes ; and 

 the back is smooth and destitute of any special marks. In C. rufa, 

 the lower lip presents a constant notch ; the lateral processes 

 are small and pointed, and the notch for the avicularium is very 

 shallow and inconspicuous ; and the back of the cell is occupied 

 by a broad mesial band connected inferiorly with two narrow 

 lateral ones, and sending off superiorly on each side a narrow 

 band to join the lateral in the avicularian processes. In this and 

 the next species the fenestra are probably formed by the opening 

 of small tubercles. 



Explanation of Figures. 



Plate 24.— Fig. 5, natural size. Fig. 5a, front view of ovicell, with other cells attached, 

 magnified. Fig. 5b, front view of a branchlet of cells, magnified. Fig. 5c, back view of ovicell, 

 magnified. Fig. 5d, back view of branchlet, magnified. 



Plate 24, Fig. 6. 

 CATENICELLA CRIBRARIA (Busk). 



Description. — Cells oval or subglobular. Surface cribriform, with a suboral 

 lunate pore, the circumferential foramina being* largest. Lateral processes destitute 

 of superior appendage, deeply excavated for the reception of the avicularia, and 

 produced inferiorly as a narrow fringe along; the side of the cell. Back of cell 

 smooth. 



Reference.— Busk, Voy. Ratt., i., 359; Cat. Mar. Pol. Brit. Mus., t. 5, f. 3, 4. 



Queenscliff, Sealers' Cove, Western Port, and other localities. 



Explanation of Figuees. 



Plate 24. — Fig. 6, natural size. Fig. 6a, front view of a branchlet of single and double cells, 

 magnified. Fig. 66, back view of cells, magnified. 



[20] 



