SCHIZOPORELLA. UNICORNIS. 239 



sometimes placed near the top of the cell, and pointing 

 straight upwards. Ocecia globose, prominent, rather 

 smooth in front, with grooves radiating from the centre 

 towards the base. 



Polypides large, with a remarkably long oesophagus 

 of a greenish-yellow colour; tentacles 18, forming a 

 very tall and graceful bell. 



Form ANSATA. Zoopcia short, broad, and squarish, usually 

 granular, and with a raised line round the border; 

 mucro often rudimentary. Ooecia small, very closely 

 united to the cell above, indistinctly grooved. 



Colonies forming large spreading crusts, often (in the 

 littoral variety) of a beautiful silvery whiteness. 



RANGE OF VARIATION. The forms which Johnston named 

 Lepralia unicornis and L. ansata must be referred to 

 one species ; there are no characters of any importance 

 separating the one from the other. L. ansata, as com- 

 monly understood, represents a deep-water condition of 

 the species, distinguished by its short, broad zooecia with 

 dense and usually granulous walls and a somewhat flat 

 surface, and by its small ovicell, on which, owing to the 

 thickened and incrusted state of the zoarium, the peculiar 

 sculpture is inconspicuous. All the essential characters 

 are identical in the two forms. The shape of the zooecium 

 has been taken as the distinctive feature of L. ansata ; 

 but this is a most variable character ; and although there 

 is no doubt a variety specially distinguished by its short, 

 broad cells, yet this type of cell is commonly found along 

 with the more elongated form on the same specimen. 



In breadth and length, and in the proportion of breadth 

 to length, the zooscia vary endlessly. They are found 

 very broad and almost square, at times broader than long; 

 rectangular, but elongate, sometimes much produced and 

 MTV narrow; ovate, and occasionally subglobose. No 



