AMASTRA. 23 



and from this region; and would suggest that the Kahuku 

 deposit be considered type locality. The species was doubtless 

 once spread along the whole north shore. 



Many Kahuku shells (pi. 2, figs. 5 to 8) retain the color, 

 orange-cinnamon above, fading to cinnamon-buff on the last 

 whorl, or only the spire or the summit may be tinted, or the 

 whole shell bleached white. The lip is blunt in adult shells. 

 The columellar lamella is moderately strong, and does not 

 quite reach the edge of the columellar lip. The latter is 

 straightened, with a basal sinus which is filled up in old 

 shells. 



Length 11.5, diam. 6.2 mm. ; 6 whorls. 



Length 10.25, diam. 6 mm. 



Length 11.3, diam. 6 mm. 



Length 9.6, diam. 6 mm. 



The last measurement is that of a scarcely adult shell, the 

 broadest of a considerable series. 



Specimens from Laie and Kailua are similar, but have lost 

 all color. 



The exact locality in Molokai where Dr. Newcomb obtained 

 living umbilicata is not known. In one of the lots sent to 

 the Academy it was mixed with petricola. So far as we 

 know, neither species has been found by recent collectors ori 

 that island. We can find nothing in the shells to separate 

 Newcomb 's specimens from those of Oahu, but the fossil form 

 from Molokai seems somewhat different. 



A. UMBILICATA ARENARUM P. & C., n. Subsp. PL 2, figS. 1 to 4. 



The shell is decidedly larger than umbilicata. It differs 

 from morticina by having the spire more slender at first, then 

 rather rapidly widening. 



a. Length 14, diam. 7.5, aperture 6.25 mm. ; 6% whorls. 



a. Length 13, diam. 6.3, aperture 5.3 mm. ; 7 whorls. 



b. Length 14, diam. 7.75, aperture 6.5 mm. ; 61/2 whorls. 

 b. Length 14.75, diam. 7.1, aperture 6.1 mm. ; 6% whorls. 



b. Length 12.3, diam. 7.2, aperture 6 mm.; 6% whorls. 



c. Length 11, dia,m. 6.5 mm. 

 c. Length 12, diam. 7 mm. 



