1920.] NATURAL SCIENCES OF PHILADELPHIA. 365 



3. Apical part of the lip biangulate at summit; diameter slightly 



less than half the length 4 



Lip not biangulate at summit; diameter about half the length; 

 19 X 9.5 mm A. kekele n. sp. 



4. Shell conspicuously widest below the middle... A. dehilis Pse. 

 Shell widest about the middle 5 



5. Surface axially weakly plicate; 5 x 2.3 mm A. costulosa Pse. 



Without noticeable axial sculpture; 10.6 x 4.8 mm. 



A. cornuta Pils. 



Atys semistriata Pease. 



Proc. A. N. S. Phila., 1917, p. 217, fig. 5. 



The specimen in the Pease collection which I figured is larger than 

 any others seen, few of which exceed 10 mm. in length. Typically 

 it is distinctly wider below the middle, but sometimes the greatest 

 diameter is nearly median. There is also variation in the number 

 of engraved lines on the lower third, which are often less numerous, 

 perhaps always so in the immature shells. Specimens seen are 

 from Kauai: Hanalei River and Haena. Oahu: Waikiki beach, 

 Kahala and Waimanalu. Maui: Kahului dunes (Bryan). Kahoo- 

 lawe (Pilsbry). 



Atys semistriata mua n. siibsp. 



The shell is decidedly compressed near the summit which is nar- 

 rower than in the typical form. 



Honolulu (Pilsbry, 1913). 116611 A. N. S. P. 



Atys semistriata fordinsulae n. subsp. 



Greatest diameter about median; about 10 spiral grooves above 

 and below. Length 10.5, diameter 6.3 mm. Ford's Island, in 

 Pearl Harbor (W. A. Bryan). 



Atys kekele n. sp. Figiire 4. 



The shell is oblong, widest below the middle, tapering slowly 

 posteriorly to the rather narrow, angular vertex; outline towards 

 the base rather strongly convex. Near the summit there are 8 or 

 9 spiral grooves, the lower ones widely spaced. The convex base 

 has numerous finer and closer linear grooves. Vertex rather deeply 

 excavated. The aperture is very narrow in the upper half, moder- 

 ately dilated below. There is a strongly salient, compressed fold 

 in the sloping upper margin of the Up. Columella rather thick, 

 nearly straight, joining the basal margin in a short curve. Basal 

 margin retreating. 



