Dentition of Puhnonate Mollusks. 99 



Leptachatina grana, Xewc. W. Maui. 

 Dentition as in last species. 



Leptachatina dimidiata, Pfr. Oahu. 

 Same dentition. 



Leptachatina tciiilis, Fer. 



The dentition is as in the other species of the subgenus examined by me. 

 There are 2G-1-26 teeth, with eight laterals on each side. On PI. VI, tig. G, 

 I figure the whole change from central to extreme marginal teeth. The last 

 are not pectinate. 



Tornaiellina. 



Considered by von Martens as a sub-genus of Cionella, but by 

 its dentition closely related to Achaiinella, s. s. The jaw was 

 not examined. 



Tornateltina aperta, Pease. Huahine Island. Mr. A. Garrett. 



Lingual membrane (PI. Ill, fig. F). The figure represents the central, 

 with the first and second side teeth. There is an exceedingly large number 

 of teeth beyond this, of the same type, quite to the exterior margin of the 

 membrane, The teeth are arranged obliquely in waving rows, as is also 

 the case in Achatinella, s. s. Teeth of same type as those of Acliatinella, s. s. 



Tornaiellina oblonga,~Pea$e. Huahine Island. Mr. A. Garrett. 



Lingual dentition the same as in the preceding species. 



Claasilta. 



The West Indian species alone examined. 



Clausilia tridens, Chemn. Porto Pico. Mr. Robert Swift. 



Jaw (PI. XV, fig. .7) slightly arcuate, smooth, wide, low: ends slightly 

 attenuated, blunt; cutting edge with a blunt, wide, median projection. In 

 the jaw figured, the lower margin is developed, but much thinner, beyond 

 the cutting edge. 



Lingual membrane (PI. VII, fig. H) short and broad, Avith about 30-1-30 

 teeth. Centrals with long, narrow base of attachment, incurved at the 

 sides and base, where it is also excavated or thinned, rounded at top, and 

 reflected; reflection small, with one large cusp bearing a short, blunt, cut 

 ting point, and sub-obsolete side cusps; laterals like centrals, but asymmetri- 

 cal, the base of attachment much wider, the reflection and cusp with its cut- 

 ting point much stouter and longer; outer laterals with distinct side cusp 

 and cutting point; the base of attachment of the laterals is squarely cut 

 away on its inner angle; about the eleventh tooth the teeth begin to change 

 to marginals; the extremes of which last are subquadrate, wider than high, 

 broadly reflected into a large cu^p bearing two oblique, large, irregularly 

 bifid cutting points. 



