244 AMASTRA, LANA1. 



lip acute, submarginate within; color rosy, partly concealed 

 by a thin brown epidermis ; upper whorls black ; aperture red 

 within. (Newc.) 



No dimensions ; figure measures 23 x 12 mm. 



Lanai (Newc.) ; Waiapaa >and Koele (Perkins). 



Achatinella biplicata NEWC., P. Z. S., 1853, p. 156, pi. 24, 

 f. 75 (1854). THWING, Orig. Descriptions, p. 168, pi. 3, f. 

 19. Amastra biplicata Nc. SYKES, Fauna Hawaiiensis, p. 

 334. 



A variable shell, sometimes quite elongate, sometimes short- 

 ened, but typically easy to recognize by the biplicate colu- 

 mella and more or less deeply pink aperture. An embryonic 

 shell 3.8 mm. long, of nearly 3 whorls, has an angular peri- 

 phery, moderate columellar fold and no perforation. The 

 first half whorl is smooth; next whorl finely and sharply 

 striate, and the following whorl is much smoother. The em- 

 bryonic whorls are invariably dark purple-brown. Later 

 whorls of the shell are quite convex, with rather low, coarse, 

 irregular growth- wrinkles. Cabinet specimens are whitish 

 under the dense black or black-brown 1 cuticle, which may be 

 nearly continuous or very extensively deciduous. On the 

 intermediate whorls the cuticle is generally mottled, or re- 

 mains in forwardly descending stripes, which are probably 

 due to an oblique malleation of the surface. The aperture is 

 pink-tinted or white within, the outer wall is sometimes thin, 

 but generally thickened by a heavy deposit of callus, forming 

 a low entering ridge above the middle of the outer lip. This 

 has been noticed in few Amastras. The columella sandf 

 parietal wall are pink. The columella usually bears two sub- 

 equal, oblique folds, but occasionally the upper one is weak 

 or entirely wanting, and in one shell examined (no. 13433, 

 B<oston Society) there is no trace of an upper fold, and the 

 lower one is reduced to a low truncation of the 'columella. 



Length 23, diam. 11, aperture 9 mm. ; 7% whorls. 



Fig. 4. Length 20.5, diam. 11, aperture 9 mm. ; 6% whorls. 



Fig. 6. Length 22, diam. 10.2, aperture 8.9 mm. 



A. durandi Ancey, said to be from Waianae, Oahu, but 

 known to occur on Lanai, is apparently the most closely re- 



