Descriptions of New, or Little Known, Polyzoa. 129 



the marginal cells there are three spines at the upper and 

 outer angle, and one at the inner; in the central cells 

 a single spine at each side ; a sessile avicularium (usually 

 absent) attached to the upper and outer angle of the lateral 

 zooecia ; a sessile avicularium on the front of each zooecium, 

 except the lateral, usually close to the peduncle of the fornix 

 of the adjoining cell. Zooecia posteriorly quadrate, smooth, 

 or faintly longitudinally sulcate. Ocecia prominent, rounded, 

 smooth. The radical fibres forming the lateral bundles 

 spring from the lower part of the back of the cells. 



Port Phillip Heads. 



Closely allied to Busk's M. benemunita, but distinguished 

 by the absence of the two avicularia on the front of the 

 central zooecia, and the different form of the fornix. 



Caberea Darwinii, Busk. 



In the Challenger Polyzoa, Mr. Busk describes and figures 

 a form from New Zealand under this name, which, he says, 

 is identical with that previously described in the British 

 Museum Catalogue as C. Boryi, and marked on the plate 

 G. patagonica. It is not uncommon in Victoria, and I quite 

 agree with Busk in considering it as distinct from the 

 European species. It is characterised by the zooecia being 

 narrowed downwards, the lower parts and sides of the area 

 filled in by a granular layer, with the edge of the aperture 

 finely crenulated. In perfect specimens the fornix is of 

 large size, filling the whole aperture, except the part corre- 

 sponding to the mouth. It is nearly straight above, with 

 frequently a small process or spur projecting upwards, and 

 the large, downwardly extending lamina has a peculiar 

 helicoid marking, with the spiral turned inwards. Busk 

 does not describe or figure this appearance, showing the 

 lamina as plain, but there can be no doubt of the identity of 

 the species. A somewhat similar, but less developed mark, 

 is seen in an English specimen of C. Boryi. In older 

 specimens the edge of the lamina is usually worn off, and it 

 then has a reniform or hammer-shaped appearance. The 

 ovicell when young has the margin smooth, but this gradu- 

 ally becomes surrounded by a thickened band, 



C. glabra, n. sp. 



Zoarium expanded, flabelliform. Zooecia biserial, slightly 

 narrowed below, area partly filled in by a smooth plate. 



K 



