214 PARTULA, RAIATEA AND TAHAA. 



Group of Partula dentifera. 



These arboreal snails of Raiatea and Tahaa are character- 

 ized by the usually light yellow color of the shell, the sum- 

 mit white, yellow, pink, or purple-tipped; lip white, thick- 

 ened within, more or less strongly toothed within the outer 

 lip and excised above the tooth. Columella and parietal 

 wall often toothed. The species are closely related to some 

 of the faba group. 



a. Shell denuded of cuticle, openly umbilicate; aperture 

 rounded-oval, with two or three strong teeth. 



P. callifera, no. 22. 

 aa. Cuticle present; aperture ovate. 



b. Lip heavy, keeled on the face, with a heavy tooth 

 above ; no columellar or parietal teeth. 



P. dentifera, no. 24. 

 bb. Lip thinner, its face not keeled, tooth smaller. 



c. No parietal tooth, but having a columellar 



tooth; umbilicate, greenish-yellow, length 



23 mm. P. citrina, no. 25. 



cc. Parietal tooth usually developed; nearly or 



quite imperf orate; length 17 to 21 mm. 



P. imperforata, no. 26. 



Properly speaking, this group consists of only three species : 

 P. callifera of Haamoa valley, Raiatea ; P. solidula of unknown 

 locality, and P. dentifera, of which formosa, citrina, imper- 

 forata and virginea are scarcely more than subspecies, spread 

 over Raiatea and part of Tahaa. P. imperforata raiatensis 

 and virginea are apparently the least modified survivors of 

 the original stock. 



22. P. CALLIFERA Pfeiffer. PI. 20, figs. 1, 2, 3. 



Shell umbilicate, ovate-conic, solid, nearly smooth (under 

 the lens punctate-striate) , whitish. Spire a little eonvexly 

 conic, rather obtuse. Suture light. Whorls 5, a little con- 

 vex, the last a little longer than the spire, inflated. Columella 

 subvertical, bearing a tubercle above, folded within. Aper- 

 ture slightly oblique, sinuous-oblong, contracted by a deeply 



