244 



On the Lingual Dentition in the Gasteropoda, 



differ more strikingly from the plummet, as shown in the 

 following table : — 



Were all the genera included in each system given in ex- 

 tensOj a very much greater difficulty would present itself to 

 the mind of any one attempting to reconcile their differences. 

 Enough has been said, however, to show that the lingual 

 dentition would appear to be the only appeal. Indeed the 

 effort to accomplish this desirable object in any other way 

 would only lead to unscientific dispute, and develop no satis- 

 factory result. 



In a subsequent paper I shall consider the relationships of 

 all the families of proboscidiferous Gasteropoda in which the 

 central and often the pleural teeth point directly backwards 

 without recurvature — in short, the Orthodontal Proboscidifera. 



Haslar Hospital, Sept. 11, 1868. 



* Guide to MoUusca, vol. i. 

 \ Genera of Mollusca. 



t Manual of Mollusca. 



§ Omitted in Muricidse above. 



