Dentition of Pulmonata. 32 



I found it to be ribbed, a character placing the shig in the 

 genus Pallifera. The presence of ribs was verified in four 

 individuals. Small specimens of T. Caroliniensis from the 

 same locality had the usual ribless jaw of Tebennophorus. 

 It appears, therefore, that the slug must be considered a new 

 •species oi Pallifera.* It may be called after its discoverer. 

 It is difficult to draw more satisfactory specific characters 

 from specimens preserved in alcohol. One of them in its 

 contracted state measures 12 millimetres in length. 



Jaw (pi. II, fig. i) arcuate, ends blunt, but little attenuated; anterior 

 surface with decided, separated, unequal ribs, denticulating either margin, 

 about 15 on one specimen, those at the ends being less developed than on 

 the balance of the jaw; cutting edge with a decided, short, blunt, jnedian 

 projection. 



Lingual membrane (pi. II, fig. n) long and narrow. Teeth about 35- 

 1-35. Centrals long, expanding towards the base, cusp stout, with a 

 stout blunt cutting point not reaching the lower margin of the base of 

 attachment, side cusps obsolete. Laterals same as centrals, but unsym- 

 metrical. Marginals (b) low, wide, with one inner, long, oblique, blunt 

 cusp, and one outer, short, usually bluntly bifid cusp, 



Bulimus foveolatus, Rve. {Orphnus.) 

 Northern Peru. Prof. Orton. 



This and the other species collected by Prof. Orton were 

 determined by Mr. Bland. 



Jaw slightly arched, wide, low, thin, with over 50 delicate ribs of the 

 kind herewith described under Bulimulus Lohbi: ends but slightly at- 

 tenuated, blunt. 



Lingual membrane (pi. I, fig. in) long and narrow, composed of very 

 numerous rows of about 34-1-3'! teeth each. Teeth as usual in the Heli- 

 cidce. The centrals (a) with one short cusp, the side cusps being obso- 

 lete, cutting point short, bluntly pointed. Laterals like the centjals, but 

 unsymmetrical, and with a more developed outer side cusp. Marginals 

 6, a simple modification of the laterals, smaller, higher than wide, with 

 the cutting point longer. The plate gives one central with its adjacent 

 lateral, a, and three extreme marginals, b. 



The membrane is very thick and strong, and of equal width throughout 

 its length, the ends being bluntly truncated. 



* Its dentition is more related to Tebennophorus than to Pallifera by the absence of 

 Bide cusps and cutting points to the central and lateral teeth. 



