this opportunity of thanking those gentlemen for the 

 kind manner in which each has responded to my requests. 

 The names given to the shells are those of Professor 

 Forbes and Mr. Hanley, as printed in their " British 

 Molluscai" and the localities (of shells) in this neigh- 

 bourhood, unless otherwise recorded, are on my own 

 authority. 



Cycladid^. 



This is an interesting group of bivalve fresh-water 

 shells, to which the Cyclas and Pisidium families 

 belong. They inhabit rivers, lakes, and ditches, living 

 buried in the mud. They are all ovoviviparous, and 

 thrive well, and breed, when in confinement. 



Cyclas rivicola (The River Cycle). Leach, 

 Figures I and 2. 



This is the largest of the Cyclas family, Tt is nearly 

 oval, tolerably ventricose, opaque, and rather strong. 



