72 PLACOSTYLUS, NEW HEBRIDES. 



P. HETEROSTYLUS Pilsbry. n. sp. PI. 7, figs. 11, 12. 



Shell imperforate, oblong-oval, solid arid strong, uniform olivaceous 

 brown, or yellowish with brown streaks, the earlier whorls and 

 usually a subsutural strip denuded of cuticle, the spire dull red. 

 Surface smoothish, with slight growth- wrinkles which in places are 

 interrupted, giving the appearance of subobsolete spiral sulci, and 

 often with some impressed sulci plowed upon the surface of the last 

 whorl ; a strong lens showing a dense criss-cross scratched micro- 

 scopic pattern. Spire short, the apex obtuse, whorls 4j- to 4J, con- 

 vex, the last oval. 



Aperture oblong-ovate, blue in the throat, dirty yellowish or nearly 

 white near and upon the peristome ; peristome blunt, slightly ex- 

 panded, thickened within ; columella heavy, concave above, decidedly 

 truncated at base, its edge reflexed and adnate. Parietal callus mod- 

 erate or heavy, transparent or white. 



Alt. 351, diam. 18-J, length of aperture 22 mill. 



Alt. 32, diam. 17, length of aperture 20 mill. 



New Hebrides. 



Allied to P. fuligineus, but less wrinkled, the spiral sulci almost 

 obsolete, and with much shorter, more obtuse spire, only 4^ to 4^- 

 whorls, and much heavier and truncated columella. 



P. ALIENUS Pilsbry. PL 8, figs. 18, 19. 



Shell imperforate, subcylindrical, with conical spire, very solid, 

 the body-whorl buff (denuded of cuticle in the type), spire tawny. 

 Surface with slight growth-wrinkles, stronger below the sutures. 

 Whorls 4-J, convex, the penultimate whorl much more convex, bulg- 

 ing, the last whorl contracted, with a shallow peripheral sulcus on 

 its latter third, tapering toward the base, where a strongly convex 

 ridge or basal fascicle borders the umbilical region. 



Aperture slightly exceeding half the total length of the shell, 

 somewhat oblique, oblong ovate, ochre tinted inside, becoming orange 

 toward the lip; peristome expanded, thick, very heavily calloused 

 within, the callus orange ; face of the lip convex, thickened; columella 

 arcuate, reflexed, a little flattened as in P. salomonis ; just above its 

 junction with the parietal wall there is a strong fold, produced by 

 the strong crescentic ridge which encircles the columella immediately 

 behind the reflexed columellar lip. 



