12 New Species of Amastra. 



cylindrical, in some cases, the surface showing an indication of 

 indistinct malleation. The aperture is slightly oblique, rather nar- 

 row, with a regular convex outer margin, furnished with a thick 

 strong lip-rib. Columella short, almost perpendicular. Columel- 

 lar fold submedian in position, rather weak, terminating gradualK- 

 close to the margin of the columella. 



I^ength 12.5, diam. 6.7, apert. 5.8 mm.; 65'2 whls. (Holotype) 

 '' 13-6. " 7.2, " 5-7 " 6>^ " 

 " 10.8, " 6.2, " 5.0 " 6^ " 



Kauai: Pleistocene of Koloa (Stokes) ; Mahalepu and Kipu- 

 kai (Cooke). 



Holotype and cotypes No. 41,997. paratypes No. 35,809, 

 Bishop Museum. 



Very abundant in the Pleistocene deposits under the sand 

 dunes of all the above localities, associated with, but not as abund- 

 ant as A. similaris. This form is for the present placed as a 

 variety of A. rugulosa, though it may prove ultimately to be 

 worthy of specific rank. The shells of this variet}^ are for the 

 most part slightly longer and considerably narrower than those of 

 A. rugulosa or any of its varieties. The narrow extended embry- 

 onic whorls are also a distinctive character. This variet}- is 

 geographically related to A. r. normalis, live specimens of which 

 are still abundant on the northern slopes of the mountain range, 

 which cut off the southern beaches from the rest of Kauai. 



A. rugulosa var. annosa, n. var. 



PL A. Fig. 9. 



The shell is perforate, dextral, elongate-conic, rather thin, 

 in its fossil .state of a dull tawny olive color. The embryonic 

 whorls are nearly smooth, the other whorls (due to the slightly 

 worn state of all the specimens) are indistinctly obliqueh'- and 

 irregularly sculptured with growth-wrinkles. The aperture is 

 diagonal, oblic[ue, slightly contracted above, with a very convex 

 outer margin, furnished with a thick lip-rib. Columella narrowly 

 triangular, slightly bent backwards, its outer margin indistinctl}' 

 thickened and united with the outer margin of the peristome by a 



thin parietal callus. Columellar folds weak, oblique, terminating 



[230] 



