Zoology.-] NATURAL HISTORY OF VICTORIA. IPoli/zoa. 



This seemingly common species, whicli I have dedicated 

 generically to my friend Mr. J. Bracehridge Wilson, was first 

 described by Mr. Busk and doubtfully referred to Mucronella. It 

 attains a height of one or two inches. In the younger parts of the 

 zoarium the zooecia are veiy distinct, but, as age advances, the 

 divisions between them become much fainter, the zooecia them- 

 selves are squarer, and the mouth appears as a circular opening 

 surrounded by a tumid border. Many of the zooecia are then also 

 closed. On the free edges of the lobate branches, in most speci- 

 mens, there is a single row of avicularian cells, the triangular 

 mandibles of the avicularia having projecting articular processes 

 at the lower angles One very young specimen (Fig. 7) rises as a 

 small bifid lobe from an encrusting base. Towards the edge of 

 the encrusting part many of the zooecia are closed or not properly 

 formed, while, both external and internal to these, are some in 

 which the mouths have clear, narrowly elevated margins, with an 

 apiculate mucro below and, in a few, a broadly elliptical avicularium 

 across the front of the lower lip. 



Explanation of Figures. 



Plate 158. — Fig. 6, specimen, natural size. Fig. 6a, portion towards the periphery, 

 showing normal zooecia. Fig. 66, two aTicularian cells from the margin of a lobe. Fig. 6c, 

 older zooecia towards the base of the specimen, two completely closed. Fig. 7, young specimen, 

 growing from an encrusting base, natural size. Fig. 7a, two zooecia from encrusting part, 

 showing apiculate process and oral avicularium. Fig. 8, opercula and mandible of avicularium 

 from edge of a lobe. 



Mr. MacGillivray has kindly contributed the specimens and 

 descriptions of the above species of the genera Farciminaria and 

 Bracehi'idgia. 



Frederick McCot, 



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