CONIA. 



contrary, when this valve adheres to an uneven and I'oug^h 

 surface the growth of the whole shell is comparatively 

 irregular : and when the shell is full grown the radii cannot 

 always be traced on the oustide. The operculum, as in Bala- 

 nus, is bipartite ; it consists of four valves, two of which are 

 anterior, and the other two more prominent valves are 

 posterior ; the opening for the passage of the tentacula or 

 feet is between the two anterior valves. 



The Coniae are found attached to rocks, stones, shells, 

 &c. in the Mediterranean, the West Indian and various 

 other seas; we believe none have been as yet observed on 

 our coasts, nor have we ever seen any fossil species. 



Our plate represents, at 



Fig. 1. Several young specimens of Conia porosa upon a fragment of a Patella. 



2. A group of Conia porosa in various stages of growth ; in this state it is 

 the J3alanus stalactiferus of Lamarck, but not the B. Cranchii of Leach. 



3. An operculum taken out of one of the specimens of this group. 



4. & 5. Tw'o views of a specimen of Conia JLyonsii ? Leach's MS. 



