PARTULA, RAIATEA AND TAHAA. 245 



Partula suturalis PEASE, P. Z. S. 1864, p. 675, nude name, 

 (not of Pfeiffer). 



The callous rim and * * tooth ' ' within the outer lip are more 

 strongly developed than in P. faba, fusca and their immedi- 

 ate allies. There is an Oblong callous lump on the face of 

 the columella, more or less visible in different examples. The 

 white border below the suture is an important feature of the 

 species, very rarely wanting. P. planilabrum is larger and 

 more elongated than P. bilineata, and the surface is not so 

 smooth and shining. The structure of the peristome is similar 

 in the two shells, but the aperture is more elongate in 

 planilabrum. The parietal tooth is constant in adults but 

 varies in size. The following color-forms are found. 



PI. 18, figs. 2, 3. The type is deep chestnut-brown, gradu- 

 ally fading into yellowish corneous towards the sutural line; 

 the whitish lip is frequently tinged with violet. 



PL 18, fig. 4. Fulvous yellow, with the basal half of the 

 body- whorl and a revolving band below the whitish subsutural 

 border, deep chestnut-brown. Not infrequent. 



PL 18, fig. 1. Pale corneous or light fulvous with indis- 

 tinct oblique streaks. Rare. 



Numerous specimens from Pease and Grarrett show it to 

 be rather constant in form, but some shells show an angle on 

 the last whorl, in front of the aperture. Grarrett writes: 

 44 The metropolis of this species is Haamene valley, on the 

 east coast of Tahaa, where it is common, and, though usually 

 lurking beneath decaying vegetation, is sometimes found ad- 

 hering to the trunks of the wild banana. It is found, though 

 less abundant, in a valley north of its specific centre, but does 

 not occur in the intermediate valley Faa-apa, the home of 

 bilineata. ' J 



40. P. BILINEATA Pease. PL 19, figs. 8, 14. 



The shell is rather openly umbilicate, ovate-conic, solid, 

 smooth and glossy, marked lightly with growth-lines. Spire 

 almost straightly conic, the apex frequently dark. The suture 

 is margined with a white line. Ground-color whitish-corneous, 



