FRESHWATER AND LAND SHELLS. 101 



Remarks. — It is much to be regretted that Professor Nuttall was 

 unable to procure a mature specimen of this beautiful species. The 

 description being made from a young individual is, of course, defective. 

 It is impossible to say whether it be umbilicate and whether it may 

 possess a reflected lip when mature. It may also acquire a much lar- 

 ger size. It is remarkable for a dark brown and a white band on the 

 carina. That part of the specimen which has the epidermis, presents 

 in it, under the microscope, a remarkable waved appearance. 



SucciNEA APERTA. Plate XXIII. fig. 107. 



Testa subrotundd, tenui, jlavescente, Icevi; spird brevissiraa; anfraclibus binis, ultimo 

 grandissimo ; aperturd latissima. 



Shell subrotnnd, thin, yellowish, smooth; spire very short; whorls two, the last 

 being very large ; aperture very wide. 



Hab. Banks of Columbia River. Professor Nuttall. 



My Cabinet. 



Cabinet of Professor Nuttall. 



Diam. -4, Length '5 of an inch. 



Remarks. — This is one of the interesting shells brought by Mr 

 Nuttall. It is remarkable for its fullness, for the size of the last whorl, 

 and its mammiform apex, which is remarkably small. 



Paludina Nuttalliana. Plate XXIII. fig. 89. 



Testa subglobosa, cornea, Icevi ; suturis subimpressis ; anfractibus quaternis ; aperturd 

 alba, subrotundd. 



Shell subglobose, horn-coloured, smooth; sutures rather impressed; whorls four; 

 aperture white, nearly round. 



Hab. Wahlamat, near its junction with the Columbia River. Pro- 

 fessor Nuttall. 



YI 2 A 



