Zoology.-] NATURAL HISTORY OF VICTORIA. [Pohjzoa. 



the Bicellariidse. It is also closely related to the Membraniporse 

 through the very interesting B. radicifera, in which the original 

 disjunction of the cells is shown by the short, thick, calcareous 

 connection seen behind, and the avicularia, although sessile, are 

 evidently a modification of the capitate form. 



Explanation of Figures. 



Plate 117. — Fig. 1, two zocecia of a series arranged end to end. Fig. la, single zocecium 

 with the first zooecia of two branches springing from the sides. Fig. 2, outline of side view, 

 to show the position of the attachment of the connecting tubes. 



■/ki/->. .i ~ j-d^fc Plate 117, Fig. 3. 



.^ojotW f (jio +4o8 



— BEANIA COSTATA (Busk sp.). 



Description. — Zoarium adnate or free; zooecia connected with six others by 

 corneous tubes ; boat-shaped, rounded at either end ; 4-0 spines above the mouth, 

 and about 10 or 12 long- incurved spines on each side of the aperture bending- over 

 the front, and tbose of opposite sides interdigitating ; posterior surface of cells 

 smooth; a capitate avicularium on each side opposite the mouth, usually directed 

 upwards. 



Reference. — Diachoris costata, Busk, Challenger Polyzoa, p. 60, xxiv. f. 4. 



Port Phillip Heads. 



This species is allied to the D. spinigera, from which, however, 

 it may readily be distinguished. The zocecia are much smaller, 

 the marginal spines more numerous and longer, and the avicularia 

 are smaller, narrower, and more elongated. 



Explanation of Figures. 



Plate 117.— Fig. 3, group of zooecia, magnified. Fig. 3a, single zocecium, more highly- 

 magnified ; the outward direction of some of the marginal spines is owing to the irregular 

 contraction of the sides of the cell in the dried specimen. Fig. 3b, back view of portion of 

 same specimen. 



Plate 117, Figs. 4 and 5. 

 BEANIA CROTALI (Busk sp.). 



Description. — Zoarium loosely adnate or snberect; zocecia erect, quadrate, each 

 joined to six others by corneous tubes; from each upper angle a large lanceolate 

 process (a modified avicularium) is directed downwards and inwards ; posterior 

 surface with several perforations at the base and on the sides. 



Reference. — Diachoris Crotali, Busk, Cat. Mar. Pol. Brit. Mus., pt. 1, p. 54, 

 t. lxvi., figs. 1 and 2. 



Port Phillip Heads ; Portland, Mr. Maplestone. 



[68] 



