LEPRALIA. 327 



the mouth there is, on each side, a single fine spine, which 

 may be compared, perhaps, to a cat's whisker. The pat- 

 tern of the ornamented centre will be best understood by a 

 reference to the Plate. In the middle of all there is a knob 

 or projection (more or less obvious in different individuals), 

 and round this ' umbo-like projection' there is a circle of 

 small dots or punctures. Prom this circle emanate rays, 

 or raised lines, between each of which is to be found a dot 

 or puncture, larger in size than those of the other circle. 

 These rays and stars, as they may be called, are alternate, 

 and so form a circle outside the circle that surrounds the 

 umbo. Dr. Greville discovered that the pear-shaped ter- 

 mination of each cell is delicately fluted, as represented in 

 the Plate; but this character cannot be considered a uni- 

 versal guide, as the pear-shaped termination to the cell is 

 wanting in many specimens, perhaps from the overcrowd- 

 ing of the cells. 



The species has been found, during two successive winters, 

 at Sidmouth (1851 and 1852), and is to be met with also 

 in Jersey. 



Genus XIV. MEMBEANIPOEA, Slainville. 

 Gen. Char. Polypidom incrusting, membrano-calcareous, 



