110 PARTULINA, SECTION BALDWINIA. 



(d) Brown, with subperipheral white 'band, and zigzag 

 white stripes more or less developed (figs. 10 to 12). 



Specimens more or less intermediate in pattern connect 

 these forms, which (figs. 9 to 12, Waimea Plains) live to- 

 gether in the same colonies. Pattern d changes to a streaked 

 pattern on the latter part of the last whorl in adult shells 

 (fig. 12). The embryonic shell is like that of P. confusa in 

 form except that the columella is more strongly convex. It 

 is marked with broad vertical stripes of cream-white and 

 brown, their edges irregular or zigzag. 



Length 19.7, diam. 12, aperture 9.8 mm.; whorls 6%. 



Length 18, diam. 10.2, aperture 9 mm. ; whorls 6. 



Length 17, diam. 10.5, aperture 9 mm. ; whorls 6. 



The original description of A. hawaiiensis follows. 

 ' Achatinella hawaiiensis. Shell sinistral, minutely per- 

 forated, very thin, acutely conical, apex acute ; surface rather 

 lusterless, covered with, fine lines of growth, and under a lens 

 showing extremely close and delicate decussating spiral lines ; 

 nuclear whorls faintly decussated. Color very variable, plain 

 brown or dingy white, sometimes irregularly striped or 

 mottled with brown and white, the base generally uniform 

 brown, but sometimes with undulating markings of brown 

 and white ; the only constant characters being a brown, some- 

 times interrupted, line at the periphery, bordered below with 

 a broader white line. "Whorls 6, slightly convex, the last in- 

 flated. Suture lightly impressed. Aperture oblique, oval, 

 brown, the peripheral -brown and white bands distinctly 

 marked within. Peristome acute, not thickened within, ex- 

 ternal margin straight, basal expanded, the expanded portion 

 being very thin and fragile, the columella margin reflexed 

 over the minute perforation ; color white on both face and the 

 reverse. Columella. white, very slightly developed, plain ani 

 smooth. Length 18, diam. 10^ mm. 



" Animal when extended in motion longer than the shell. 

 Mantle almost white, margin of a darker shade. Foot above 

 and below dingy white, superior portion sometimes flecked 

 with gray. Tentacles of darker shade. The dentition is the 

 same as that of the arboreal Achatinellas generally. A cen- 



