24 AMASTRA. 



Molokai : Pleistocene sand dunes of Moomomi, Cooke and 

 Pilsbry, 1913. Cotypes in A. N. S. P. and Bishop Mas. 



The measurements are from specimens from about 600 ft. 

 elevation, at top of the bluff, a ; dunes at base of the bluff, & ; 

 and low ground behind the dunes, about % mile south of the 

 beach, c, where they average slightly smaller. Figures 3, 4, 

 are normal, average specimens; figs. 1, 2, are selected slender 

 and obese shells. A few of the best-preserved shells have 

 the summit tinted pinkish-cinnamon. 



A. u. arenarum is excessively abundant in the deposits. 



A. FRAGILIS Pilsbry & Cooke, n. sp. PI. 2, figs. 11, 12. 



The shell is thin, fragile, perforate, narrowly ovate-conic, 

 chestnut brown, scarcely shining, very finely, irregularly 

 striate, and with larger stria? at irregular intervals; com- 

 monly daubed with fgecal matter and soil. Summit rather 

 obtuse ; whorls convex, the last obtusely angular around the 

 narrow umbilical slit. The aperture is oval, angular at both 

 ends. Outer lip thin and fragile; columellar lip thin, 

 straightened. Columellar lamella small, thin and very 

 oblique, not quite reaching the edge. 



Length 9, diam. 4.7, aperture 4 mm. 5i/> w T horls. 



Molokai: Pipe-line trail in upper Kaunakakai, above and 

 below the spring (Cooke and Pilsbry, Jan. 26, 1913), cotypes 

 110. 108629 A. N. S. P. and in Bishop Mus. Kalamaula 

 (Thaanum). Northwestern ravine of Kamalo, above the old 

 ditch trail ; also further east, near the western PartuUna 

 redfieldi colony (Pilsbry and Cooke). "Waikolu gulch 

 (Thaanum). 



The obtuse but noticeable angulatiou around the umbilicus, 

 and the shape of the aperture indicate that this is a narrowly 

 umbilicate species of Cyclamastra, distinguished from the 

 immediate allies of A. umbilicata by its more slender contour, 

 excessively thin shell and narrow umbilicus. In common 

 with some of its allies, it carries more or less dirt on the shell. 



The form taken in Kalamaula by Mr. Thaanum, pi. 2, fig. 12, 

 is stouter in figure, but otherwise like the types. One meas- 

 ures, length 8.5, diam. 5, aperture 4 mm., with 5 whorls. An 



