38 MARINE POLYZOA. 



to allow the outlines of the cells to be seen imperfectly through 

 them. The upper extremity of the vibraculum is bifid, and to 

 the inner horn or tooth is articulated the " seta," and from the 

 notch between the two horns there is continued nearly, if not 

 quite to the inner or lower extremity of the organ, and along its 

 upper border, a shallow groove, in which is lodged the seta when 

 in a state of rest. In most species the seta is serrated on one 

 side with distant teeth. 



1. CABEREA RUDIS. PI. XL VI. 



Multiserial. Aperture oval, margin much thickened, with a 

 strong projecting upturned spine on each side, in the central 

 cells, and with three strong and long spines on the outer side, 

 and a smaller one on the inner side in the marginal cells. Oper- 

 culum spatulate, wide, entire. Each cell of the central rows with 

 two small avicularia in front immediately below the aperture. 

 Each marginal cell with a single large avicularium in front below 

 the aperture. Vibracula slender, very transparent. Setae short, 

 not serrated. 



Caberea rudis, Busk, Voy. of Rattlesn. i. 377- 

 Hob. Bass' Strait. 



Colour dirty white. Forms a broad frondose polyzoary 2 

 inches or more in height. The branches all disposed in the same 

 plane, are flat, thick, and about -^th inch wide, composed of 4-6 

 rows of comparatively small cells, which viewed behind appear 

 lozenge or diamond- shaped, and arranged quincuncially. It is 

 not always easy to observe with accuracy the outline of the vi- 

 bracula, owing to the extreme tenuity of their walls, but the 

 groove along the upper border is very distinct, and most usually 

 has the seta lying in it. The avicularia on the marginal cells are 

 very large, but not uniform in size. Along each border of the 

 branches runs a bundle of radical tubes, the number of which 

 diminishes as the branch ascends, owing to the circumstance that 

 each tube terminates in the base of a vibraculum. 



2. CABEREA BORYI. (Cab. zelanica, PI. XVI. figs. 4, 5. Cab. 



patagonica, PL XXXVIII.) 



Cells biserial; aperture oval, pedunculate operculum expanded 

 principally downwards, and sometimes sending off a process to 

 the opposite side of the aperture ; a single spine on the inner 

 side springing from the peduncle of the operculum ; two marginal 

 spines on the outer side of the aperture. Ovicell large, arcuate. 

 Vibracula ovoid. Setae serrated. 



Crisia Boryi, And. Expl. ; Savign. Egypt, pi. 12. f. 4. 

 Selbia zelanica, Gray, Dieffenb. N. Z. ii. 292. 



