THE MOLLUSCA. 127 



Littorina littoralis. Good fresh specimens have been found. 



Rissoa vitrea. Rare. Minute, shining white. Found by col- 

 lecting and washing sand, as previously stated. 



Rissoa ulvcK. Very common. In walking along the shore we 

 frequently see patches of what the stranger would suppose 

 to be black sand ; if a portion of it be taken up it will be 

 found to be a mass of these small shells. 



Rissoa castanca. Rather rare. Found amongst R. ulvcz, and 

 similar in shape and colour, but very much larger. I 

 named this shell what I believed it to be ; Jeffries has 

 examined it, and says it is an unrecognised variety oiulvce. 



TURRITELLID^E. 



Turritella communis (the Common Cockspur). Very common 



on most parts of the shore. 

 Ccecum glabrum. A minute shell found in the fine shell debris 



and sand which I have taken home to dry in order to 



search for Foraminifera. 



CERITHIADyE. 



Apporhais pes-pelecani (the Bird's-foot Shell). A handsome 

 and not uncommon species. The lip is extended out in 

 such a way as to resemble a bird's webbed foot, from 

 which its specific name is derived. 



Cerithium reticulatum. A rather worn specimen found when 

 searching for Foraminifera 



SCALARIAD/E. 



Scalaria Turtonis (Wentle-trap, or Double Cockspur). Not 

 uncommon. A handsome shell, turreted in shape, the 

 whorls round and distinct, and crossed lengthwise with 

 rather flat, pale brown, moderately close ribs. 



