70 VALVATID.E. 



among some shells collected by Mr. Wyatt from a similar 

 deposit at Biddenham near Bedford. This sjiecies now 

 inhabits the South and Sovith-west of France^ as well as 

 the Jura and Switzerland; and it has been found in a 

 fossil state in the lacustrine beds at Amiens. 



The Natica Kingii of Forbes and Hanley (iii. p. 343^ 

 pi. ci. f. 1, 2) belongs to this family, and not to the 

 Naticida. It is the Lithoglyphus Naticoides of Ferussac, 

 and inhabits the Danube. Professor King is said to 

 have found the specimen (which is now in my collection) 

 in the bottom of a fishing-boat at Cullercoats. How this 

 Austrian and freshwater species could have got to the 

 Northumberland coast, is very difficult to say. Professor 

 King informs me that he never received any shells from 

 the Danube, and that his statement as to the Northum- 

 brian locality is perfectly correct. The question of the 

 indigenousness and unaccountable habitat of this speci- 

 men must therefore remain a mystery. 



Family III. VALVATID^. 



Body elongated, spiral : eyes placed within the tentacles at 

 their base : gill protruding beyond the edge of the mantle, the 

 respiration being aided by a tentacidar filament : sexes united, 

 or common to each individual. 



Shell having a short but symmetrical spii'e and a circular 

 mouth : operculum regularly multispiral. 



This family comprises only one genus {Valvata), which 

 was founded by the Danish naturalist, Miiller. It is 

 remarkable for its branchial apparatus, which is external 

 or protruded when the animal is moving. In this posi- 

 tion it resembles a feather, and caused GeoflFroy to give 

 to these elegant little creatures the expressive name of 

 " porte-plumet." Besides this branchial plume, the ani- 



