with the particular ufe of the numerous foramina on 

 the convex furface of the upper part, as well as of 

 the circle of tubular ones which furround it. It is 

 a native of the Indian ocean^ and is generally of the 

 iize reprefented on the plate. Its colour is an ivory- 

 white,, with a flight tinge of reddilh in fome indivi- 

 duals. 



