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



identity of the species. In older specimens the edge of the lamina 

 is usually worn off, and the appearance is then much altered, as in 

 fig. 5. The ooecium when young has the edge smooth, but it 

 gradually becomes surrounded by a thickened margin. 



Explanation of Figures. 



Plate 137. — Fig. 1, specimen, natural size. Fig. la, portion of same, magnified. Fig. lb, 

 two zocecia of same, more highly magnified, showing the lateral and central avicularia and 

 scutum. Fig. \c, another portion of the same, showing an ooecium before the development of 

 the marginal rim. Fig. Id, portion of posterior surface, showing vibracula. Fig. 5, another 

 older specimen, natural size. Fig. 5a, portion, magnified, showing the scutum worn and the 

 ooecia with thick marginal rim. 



Plate 137, Figs. 2, 3, and 4. 

 CABEREA GLABRA (McG.). 



Description. — Zoarium expanded, flabelliform. Zooecia biserial, slightly 

 narrowed below, area partly filled in by a smooth plate; scutum with a thick 

 peduncle, the mandible usually chiefly expanded downwards, reniform or hammer- 

 shaped ; two spines at the outer angle above, and one, frequently of enormous size, 

 from the peduncle of the scutum. Lateral avicularia small; central avicularia 

 large, irregularly placed above or below the peduncle. Zocecia posteriorly elongated, 

 smooth or faintly sulcate, vibracular setae serrated. Ocecia rounded, arcuate or 

 irregular, flattened in front with a thickened margin. 



Reference.— P. H. MacGillivray, Tr. Roy. Soc. Vict., 1885. 



Port Phillip Heads. 



This species differs from C. Darwinii in the smoothness of the 

 lamina partly filling the area. It is closely allied to the European 

 C. Boryi, in which the zooecia are shorter and broader and have a 

 thickened smooth band round N the aperture. The peduncular 

 spine is sometimes much hypertrophied, and I was at one time 

 inclined to describe the form fig. 4 as a distinct species (C. dola- 

 brata) characterised by the enormous size of these spines, and the 

 form of the scutum extended to a sharp point above the peduncle 

 and to a blunter end below. 



Explanation of Figures. 

 Plate 137. — Fig. 2, specimen, natural size ; the branches are made too thick. Fig. la, 

 portion of the same, magnified ; the ooecia here have not yet developed.a thickened rim. Fig. 3, 

 portion of another specimen, magnified, showing a large peduncular spine and irregularly 

 shaped ocecia. Fig. 4, portion of specimen of var. dolabrata, magnified, showing enormous 

 peduncular spines and scutum forming a sharp process above. 



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