354 POLYZOA INFUNDIBULATA. 



forms that we find in specimens from the Mediterranean Sea," Ellis. 

 Shetland Islands, and in the island of Fulah, Jameson. Scarborough, 

 W. Bean. Cape Clear, Ireland, Prof. Allman. Orkneys, E. Forbes. 

 Deep water off the coast of Northumberland, W. King. 



Fig. 67. 





Polypidom about an inch in height, affixed by a hollow, thick, and 

 very short stalk, which expands into a shallow cup with unequal 

 waved and sinuous margins ; pure white, calcareous, and beautifully 

 reticulated, the meshes about a line in length, oval, subequal, regular, 

 and divided by celluliferous spaces, rather wider than their own 

 shortest diameter ; the cells immersed, quincuncial, leaning with the 

 apertures looking upwards, a little prominent, round, with a small 

 tooth on the distal edge ; they open only on the superior or inner 

 aspect, for the under surface of the polypidom is imperforate and 

 almost smooth. 



"Dr. Johnston and others have considered this coral to be iden- 

 tical with the Mediterranean Retepora cellulosa ; but, after an exami- 

 nation of the characters of each, I have been led to conclude that 

 they are distinct species. In the Mediterranean coral the interstices 

 of the celliferous surface are furnished with strong hook-shaped pro- 

 cesses curving upwards generally two on each side of a mesh, but 

 nothing of the kind is seen in the British species ; and the under lip 

 of the cell-apertures is not provided like the latter with a tubular 

 process. Further, Retepora cellulosa has the meshes generally wider 

 than the interstices ; in R. beaniana they are not so wide. These 

 differences are not the result of age, as they prevail in old and young 

 specimens of both species ; probably there may be other differences, 

 which can only be detected by a powerful microscope. In other re- 



