314 AMASTRA, HAWAII. 



by Mr. Baldwin measures, length 15.2, diam. 7.9, aperture 6.5 

 mm. ; 6% whorls. It differs from A. melanosis by its narrow 

 contour and rounded last whorl, but is very closely related to 

 A. fossilis. The columellar margin is more broadly reflexed 

 than in the following recent forms. Above the suture an an- 

 gulation is visible as far as the middle or even the end of the 

 penultimate whorl. The following varieties also show this 

 feature. 



107a. Var. gyrans Hyatt, n. v. PI. 47, figs. 3, 4. 



Shell extremely thin, smaller than A. conica, the summit a 

 trifle more slender. Pale-brown under a thin dull-brown 

 cuticle, the colors showing through in the aperture. Colu- 

 mellar fold very small and oblique, axis perforate or rimate. 

 Embryonic whorls convex, somewhat produced, very finely, 

 sharply striate. 



Length 14, diam. 7.1, aperture 6.5 mm. ; 6 whorls. 



Length 12.5, diam. 6.25, aperture 5 mm. ; 6 whorls. 



Hawaii : Types no. 2268, Cooke coll. 



Although Mr. Baldwin expressed the opinion that A. conica 

 would not be found living, a comparison of specimens shows 

 that gyrans is practically only a somewhat smaller living 

 form of the same species, if indeed it can be discriminated 

 even varietally. 



107b. Var. kohalensis n. v. PI. 49, fig. 13. 



The shell is thicker than var. gyrans, fleshy whitish under 

 the cuticle, apex brown. The thin cuticle is yellow, copiously 

 streaked with chestnut, the streaks rather narrow; aperture 

 and parietal callus faintly flesh-tinted; columellar lamella 

 very oblique and very low, suprasutural keel well developed 

 as far as the front of the penultimate whorl. Length 15, 

 diam. 7, aperture 5.5 mm. ; 6% whorls. 



Kohala Mts. (D. Thaanum, no. 5158, communicated by Dr. 

 C. M. Cooke) . 



This form resembles Newcomb's figure of A. lineolata, but 

 the streaks are not in the lest zigzag. It may turn out that 

 Newcomb's phrase refers to some slight irregularity due to 

 wear ; yet I do not feel justified in making this assumption. 



