Dentition of Pulmonate Mollushs. 9*3 



is long and narrow, squarely truncated below, rapidly widening 

 and curving outwards at its upper third, so that the upper mar- 

 gin is twice the breadth of the lower ; it is rounded and reflected 

 along its whole breadth ; reflection small, bearing five or more 

 cusps and cutting points, the median the smallest. There is 

 some variation in these cusps. Of this type of jaw and den- 

 tition are : — 



Partulina jucunda, Smith. W. Maui. 

 plumbea, Gulick. E. Maui. 

 eburnea, Gulick. E. Maui. 

 solidissi/na, Smith. E. Maui. 

 solida, Gulick. Oahu. 

 tcsniolata, Pfr. Oahu. 

 marmorata, Gld. Oahu. 

 pallida, Xutt. Oahu. 



Achatinella (s. s.) producta, Rve. Oahu. (PI. Ill, fig. G.) 

 Jolmsonii, Newc. Oahu. 

 livida, Swains. Oahu. 

 varia, Gulick. Oahu. 

 auricula, Fer. 



In the last three species, I failed to extract the delicate jaw. 

 Achatinella auricula, Fer., on account of its having this type of 

 dentition, I remove from Partula, where it is placed by von 

 Martens. 



The peculiar type of dentition shared by the above species is 

 seen on my PI. Ill, fig. G. (A. producta, Rve.) 



(b) Of the second type of jaw and dentition are the remainder 

 of the species examined. The jaw is stout, arcuate, ends blunt, 

 no anterior ribs ; generally a median projection to cutting edge. 

 In Laminella Mastersi it is low, wide, slightly arcuate, horn- 

 colored; no median projection. (PI. XVI, fig. E.) It is the 

 same in the other species of Laminella. The same type of jaw, 

 though more arched, is found in all the species of Newcombia 

 and Leptachatina. In picta (PL XVI, fig. M) there is a slightly 

 produced, blunt, median projection to the cutting edge. There 

 are often delicate vertical strias on this type of jaw. 



