232 PROCEEDINGS OF THE ACADEMY OF [1895. 



Amastra tenuispira, n. sp. PI. XI, fig. 51. 



Shell dextral, imperforate, solid, acuminately turreted, spire 

 conical, apex subacute; surface lustreless, covered with somewhat 

 rude, irregular incremental striae; the embryonic whorls very finely, 

 radiately sulcated. Color light-brown, upper whorls darker ; 

 covered with an earthy brown, fugacious epidermis. Whorls 7, 

 somewhat convex, in some examples slightly margined above; suture 

 well impressed. Aperture oval, oblique, rather small, light-brown 

 within; peristome simple, acute, extremities united with a thin cal- 

 losity; columella sub-biplicate, light-brown, tortuous, abruptly 

 terminating in an oblique, dentiform plait. 



Length, 17; diam. 6' mm. 



Habitat, Kaala Mr., Island of Oahu. 



This species is very local in its habitat. Its only congeners are 

 the elongate forms Amastra Hidchinsonii Pse., which inhabits East 

 Maui, and Amastra moesta Newc. from the island of Lanai. The 

 former is remarkable as the only known sinistral species of the 

 Amastra section, and is also distinguished by its invariably white 

 aperture and columella fold. The latter species is characterized by 

 its more obese form and peculiar columella. 



Amastra nana, n. sp. PI. XI, figs. 48, 49. 



Shell dextral, imperforate, rather thin, ovately conical, apex sub- 

 acute ; surface lustreless, striated with fine incremental lines, the 

 2-V embryonic whorls finely, radiately sulcated. The color varies 

 from light to dark brown, the basal half of the body whorl some- 

 times of lighter shade than the upper portion ; covered with a black 

 or earthy- brown, fugacious epidermis, often laid on with alternating 

 undulations, or zigzag markings. Whorls 6, somewhat convex ; 

 suture well impressed. Aperture oval, a little oblique, white with 

 a purplish tinge ; peristome simple, very thin ; columella purplish- 

 white, rlexuous, abruptly terminating in a thin lamellar plait. 



Length, 111; diam. 6] mm. 



Habitat, Makawao, Island of Maui. 



Animal when extended in motion as long as the shell. Mantle 

 light brown. Foot above and below brown with spots of deeper 

 shade on the sides. Tentacles and front above almost black. 



This is one of the smaller of the Amastra forms. It is about the 

 size of Amastra petricolor Newc. from Molokai, and Amastra umbili- 



