232 



Note* on Lingual Dentition of MdUwca. 



but it was preserved in the same bottle as Ancylus Newberryi, 

 I' ipholp '- Fluininicola NaOuUiana^ and other species of 



! ' «st. 



I'M.. 1. 



Lingual dentition "I Sucoinea Nut$alliana. Lea. 



Lingual membrane broad. Teeth L9. 1.19, in almost straight 

 transverse rows. Centrals Bhort, stout, obtusely tricuspid, the 

 central cusp with a long acute point, attached to a quadrate plate, 

 pperedge of which has a ceDtral quadrangular spot of thinner 

 texture, easily mistaken for a complete cutting away of a portion 

 of the plate. Laterals on somewhat oblong plates which bear on 

 their outer upper corner a small quadrangular expansion, stoutly 

 and obtusely bicuspid, the larger cusp surmounted by a long 

 acute poinl ; base rounded. [Jncini on plates with rounded bases 

 and attenuated and serrated apices, irregularly denticulated. 



r. l, a shows two centrals and two laterals, with a third 

 • ;il detached; A and c show uncini from the left of the median 

 line; d the eighth lateral, partly in profile. 



Tin- jaw of Succinea Nuttalliana has a perfectly smooth an- 

 terior surface. 



ItiilBimilii* pallidior, Sowerby. 

 Lingual membrane broad, with numerous nearly Btraighl trims- 

 i' tO.1.40. t -rill. Centrals with one long hluut 



Ungual 'i< Miiihui ..f Bulimului pallidlor, Bowb. 



lian, and two ob ill Bide cusps; plate subquad rate, 



I d ;it bi :avated at its upper margin, and with small 



