142 AMASTRA, KAUAI. 



Key to Amastra of Kauai. 



a. Shell imiperf orate, large, strongly carinate (Kauaia). 

 &. Trochiform, solid, peripheral carina dominating. 



A. kauaiensis, no. 1. 

 & 1 . Oblong-conic, the last whorl with two carinae. 



A. knudseni, no. 2. 

 a 1 . Shell umbilieate ( Cyclamastra) . 



b. Periphery carinate; shell wider than high, conic 

 above, convex below. A. cyclostoma, no. 3. 



&. Periphery rounded. 



c. Globose-conic, diam. and alt. subequal. 



A. sph&rica, no. 4. 

 c 1 . Ovate- conic, much longer than wide. 



A. similaris, no. 5. 



a 2 . Shell rimate or imperforate, ovate-conic, white behind the 

 lip and around the axis (Amastrella). 

 b. Fine spiral lines on the later whorls. 



A. anthonii, no. 8. 

 &. 1 Not spirally striate. 



c. Larger, roughly striate, brown. 



A. rugulosa, no. 6. 



c 1 . Smaller, finely striate, purplish with brown 

 spire and white sutural line. A. nucleola, no. 7. 



Subgenus KAUAIA Sykes. 



Carinella PFR., Novit. Conch., iv, 1875, p. 116, for A. kau- 

 aiensis only. Not Carinella Sowerby, 1839. Kauaia SYKES, 

 Fauna Hawaiiensis, ii, pt. iv, Mollusca, May 19, 1900, p. 355 ; 

 same type. 



Shell biconic or trochiform, carinated, solid, imperforate; 

 dark brown, whitish around the axis, under a thin yellow 

 cuticle. Embryonic whorls flattened, sculptured with low 

 curved riblets, later whorls with spiral striae. Internal axis 

 tubular, contracted near the base in each whorl, in the last 

 half -whorl bearing a small columellar lamella. Type A. kau- 

 aiensis Newc. 



Kauaia resembles some specimens of Amastrella tristis in its 



