168 Jaio and Lingual Dentition of JPulmonata. 



Nanina radians, Pfr. {Microcystis). 



Rarotonga Isl., Mr. A. Garrett. 



Plate xvi, fig. 1, represents one central, lateral and marginal tooth. 

 There are 40-1-40 teeth, 8 being perfectly formed laterals. The mar- 

 ginals are sometimes trifld. 



For the identification of this and of the following Society 

 Island species I am indebted to Mr. Garrett. They form a 

 part of an extremely interesting collection of Society Island 

 land shells, preserved in spirits, just received from him, 

 through Dr. W. D. Hartman of West Chester, Pa. 



Nanina conula, Pease. 



Island of Huahine, Mr. A. Garrett. 



Central and lateral teeth as in N. radians, Pfr. (see above). Lateral 

 teeth seven in number. Marginals aculeate, multifid, very numerous. 

 The species is viviparous. 



Nanina calculosa, Gould. 

 Island of Huahine, Mr. A. Garrett. 



Jaw as usual in the genus. Lingual membrane long and narrow. 

 Teeth 38-1-38. Centrals and (7) laterals as in N. radians (see above), the 

 latter, however, have slightly developed, inner, side cutting points. First 

 15 marginals bifid, the balance multifid. 



The species is viviparous. 



Trochomorpha Cressida, Gould. 

 Island of Huahine, Mr. A. Garrett. 



Jaw arched, high; ends blunt; cutting margin with a median beak-like 

 projection. 



Lingual membrane (pi. xvi, fig. H.) with 55- 1-55 teeth. The bifur- 

 cation of the cutting point of the marginals commences in the 11th tooth. 

 There are no side cusps to centrals and laterals, which have a long, 

 narrow base of attachment. 



I figure one central, one lateral and one marginal tooth. 



Von Martens puts the species in Discus, a subgenus of Nanina. 



