New Species of Amastra. 15 



almost smooth, iudistiuctly and irregularly striate; the later whorls 

 convex, lusterless, sculptured with indistinct irregular growth- 

 lines. The last is slightly angular at the periphery, the angle 

 being continued on the penultimate whorl just above the suture. 

 The aperture is somewhat narrow, the outer lip is regularly curved, 

 slightly thickened within and margined with black. The colu- 

 mella is narrow, flattened and closeh- appressed to the shell. The 

 columellar fold is rather large, oblique, terminating abruptly at 

 the margin of the columella. 



I^ength 12.6, diam. 6.8, apert. 5.5 mm.; 6 whls. ( Holot} pe ) 

 12. 1, " 6.8, " 5.5 " 6 " 



Hawaii: Kahauloa. elevation 3,250 feet; Keauhou elevation 

 2,000-2,400 feet (ly. A. Thurston and T. C. White). 



Holotypes No. 41,964, paratypes No. 39,642, Bishop Museum. 



At first sight this Amastra appears to be a form of A. conica. 

 It differs, however, from A. conica and its varieties {gyrans and 

 kohalcjisis) in its thicker shell, closed perforation, besides the em- 

 bryonic whorls are slightly more convex and the apex less pointed . 

 Some of the specimens are more distinctly' keeled at the periphery 

 than the holotype. It is, however, in the immature specimens that 

 the differences are more apparent. The shells are broader in pro- 

 portion to their length and there is a strong distinct keel at the 

 peripher}'. A. z>.'Iiitci\i3iS a much stronger, less oblique columellar 

 fold than either A . c. gyrans and A . c. kohalensis. 



An immature specimen with five whorls measures ; length 

 9.3 diam. 5.0 mm. There is a minute perforation below, but the 

 upper part of the columellar is appressed to the shell for more than 

 half its length. A. zchitei ma^' ultimately prove to be related to 

 A . 7)icla7iosis, which Newcomb claimed to have been collected near 

 the localities mentioned above. 



A. conica var. gentilis, n. var. 



PI. A. Fig. I. 



The shell is imperforate or nearly so, elongate-conic, rather 

 solid. In its fossil state the lower whorls are white, gradually be- 

 coming darker as they ascend. The spire is narrowly conic, with 

 very slightly convex outlines, the whorls are nearly flat and separ- 

 ated by a very shallow suture. The aperture is rather narrow. 



'"233] 



