40 AMASTRA. 



sence of a callous rim within the outer lip. The embryo has 

 an obtuse summit and angular periphery, the angle sometimes 

 concealed in adult shells. Its sculpture varies somewhat, but 

 is always fine. The neanic stage has an acute peripheral angle 

 or a narrow keel, as far as the end of 8^2 to 4^ whorls, after 

 which the whorl becomes rounded. The peripheral whitish 

 band is the most constant, the subsutural band being often 

 wanting and the basal light patch mentioned in the descrip- 

 tion is generally not noticeable. The largest shell taken is 

 9 mm. long. The embryo figured is 2.3 mm. long, composed 

 of 2y 2 whorls. 



A. ALBOCINCTA Pils. & Cooke, n. sp. PL 3, figs. 11, 12. 



The shell is perforate, oblong-conic, small, thin, somewhat 

 shining, more or less daubed with dirt in life. Spire 

 straightly conic, tapering to a minute apex. Embryonic 

 whorls drawn out, strongly convex, very delicately striate, 

 having a silky luster. Neanic whorls convex, angular at the 

 periphery, the angle concealed in adults, or sometimes visible 

 just above the suture. Last whorl rounded, having sculpture 

 of irregular, delicate growth-striae, liver-brown, more or less 

 streaked with yellow, and having creamy bands at suture, 

 periphery and around the columella, the sutural and colu- 

 mellar often obsolete. The aperture is dark within, lip not 

 in the least thickened. 



Length 9.3, diam. 5 mm. ; 5% whorls. 



Molokai: northwestern ravine of Kamalo, just above the 

 ditch trail, on a steep, wooded slope. Pilsbry and Cooke, 

 Jan. 29, 1913. Cotypes 108689 A. N. S. P. and in Bishop Mus. 



This species resembles A. tricincta in size, color, and in 

 the thinness of the shell. The spire is more slender than 

 in that species, with the tip more produced and acute. The 

 embryonic shell (pi. 3, fig. 12, length 2.6 mm., of 2% whorls) 

 is more oblong, with only an indistinct peripheral angle. 



A. petricola Newc., of which we have seen a number of 

 examples, is a much more solid shell, with more obtuse apex. 

 A. pusilla Newc. is more solid than A. albocincta, with 

 coarser embryonic sculpture. A. albocincta and A. tricincta 



