136 Descriptions of New, 



branches usually more or less twisted on themselves. The 

 Zooecia are pyriform, separated "by deep grooves ; the mouth 

 is subcircular, with a broad denticle internally and occasion- 

 ally a small apiculate process on the lower lip. There is an 

 elevated ridge round the mouth, the two sides meeting 

 below the lower edge and continuing down the cell as a 

 central elevation. The surface is smooth, or, especially in 

 young cells and on the raised portion, minutely granular. 

 As age advances the divisions between the cells become 

 much fainter, the cells themselves are squarer, and the 

 mouth appears as a circular opening surrounded by a 

 broad tumid margin. Many of 'the cells are also completely 

 closed. 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 cells are closed or not properly 

 formed, while both external and internal to these are some 

 where 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. I 

 have not seen these oral avicularia in any other specimen. 

 On the free edge of the lobate branches, in most specimens, 

 there is a single row of avicularian cells. 



This species, which is common, has been described by 

 Mr. Busk in the Challenger Polyzoa, and doubtfully referred 

 to Mucronella: There can, however, be no question that it 

 ought to form the type of a new generic group, and I have 

 much pleasure in associating it with the name of my friend, 

 Mr. J. Bracebridge Wilson, who has done so much to 

 advance our knowledge of the marine zoology and botany of 

 Victoria. Its systematic position, however, is doubtful, and 

 it ought perhaps to be included in the Escharidse. 



Family Celleporim:. 



Pcecilopora, n. genus. 



Zoarium erect, bilaminate, branched. Zocecia indistinct ; 

 primary mouth, with a sinus ; peristome commencing as an 

 elevated point, with a small avicularium on the summit, 

 finally becoming a tumid, subcircular ring. Ocecia immersed, 

 closed by a perforated plate. 



P. anomala, n. sp. Plate I., fig. 9. 



Of this very curious species, I have only one good speci- 

 men, for which I am indebted to Mr. Wilson, and two or 



