POLLICIPES. 



valve is much lengthened^ broad at its base, rounded on 

 its back, and sharp pointed at its apex. Between these 

 five valves and the peduncle are a number of smaller 

 valves, which are more or less elongated, and mostly 

 triangular. AH the valves are pointed at their upper 

 ends. 



Of the three species mentioned above, and named 

 by Leach, PoUicipes Cornucopia, Blitella and villosus, the 

 first is common on the rocks in many parts of the Medi- 

 terranean, and we have seen it in large groups; the 

 second is said to have been brought from India, it is 

 extremely rare, and we have never seen the peduncle 

 complete ; of the third we have seen very few specimens, 

 and its locality is entirely unknown to us ; our specimens 

 were attached to the two valves of a Modiola albicostata of 

 Lam, in the collection of Mr. George Humphrey. 



Fossil species of this Genus are not known. 



Our plate contains representations of 



Fig. 1. PoUicipes Cornucopia. 



2. • Mitella. From a fine specimen in possession of the Rev. 



Dr. Goodall. 

 3* ■ ■ ' villosus. 



