340 ESCHARtDJS. 



inclose the rostrum, which is now within the (secondary) 

 aperture. The cells are disposed in longitudinal lines ; and 

 each series alternates with the next; so that the plan of 

 arrangement over the surface of the zoarium is quincun- 

 cial. They are divided by a very slight depression, and 

 have almost the appearance of being confluent. The 

 surface is flattish; and the raised and somewhat swollen 

 and massive peristome, with the ovicell to which it is 

 united, forms a rather large ovoid mamillary rising at 

 the top of each cell. This is the most striking feature of 

 the species. The ovicell is small and subimmersed; and 

 there is always on the front of it a depressed area, which 

 is arched above, and filled in by some slighter and pro- 

 bably membrano-calcareous material. The surface of the 

 zoarium is perfectly smooth, entire, and glossy. 



Genus SMITTIA, Hincks. 



Der. Named in honour of Prof. F. A. Smitt. 



EscHAKA (part.), auett. 



Berenicea (part.), Johnston. 



Lepralia (part.), Johnston : Busk : &c. 



EsCHARBLLA, Smitt (as limited in his paper on Bryozoa from Nova Zembla, 



CEfv. K. Vet.-Ak. Forh. 1878 : not Escharella of Gray or 



D'Orbigny). 

 Smittia, Hincks, Ann. N. H February 1879. 



Generic Character. — Zooscia with the primary orifice 

 suborbicular , the lower margin entire and dentate ; peri- 

 stome elevated and forming a secondary orifice, which is chan- 

 nelled in front ; generally an avicularium below the sinus. 

 Zoarium {in British species) either incrusting, or erect and 

 foliaceous, the cells in a single or double layer. 



For this very natural and well-defined group Smitt has 



