AURICULELLA, OAHU. 93 



iphery. The palatal fold is bifurcate near its beginning and 

 more strongly developed than in the adult. There is some- 

 times an upper palatal fold, just above the periphery. The 

 folds of the columella are strongly developed, especially the 

 lower which is almost horizontal. 



Oahu: Konahuanui, at an elevation of about 3,000 ft. (Ly- 

 man, Cooke). 



There is a great deal of variation in the columella of the 

 six adult specimens which I have before me. The columella 

 in one specimen is hardly biplicate, while in another there are 

 three distinct columellar folds. 



This species somewhat resembles A. castanea Pfr. It dif- 

 fers from the latter by having flatter and more compact 

 whorls, it is decidedly more turrited in form, besides being 

 always dextral. 



14. A. SERRULA Cooke, n. sp. PL 25, figs. 13, 14. 



The shell is imperf orate, sinistral, turrited, elongately 

 conic, light chestnut corneous, thin, diaphanous, glossy, under 

 a lens very minutely striate with lines of growth. Spire elon- 

 gately conic, apex somewhat obtuse. Suture not impressed, 

 very narrowly margined, slightly darker than the shell. 

 Whorls Sy 2> the embryonic slightly rounded, the rest nearly 

 flat, slowly increasing, rather compact, the last rotund, sub- 

 saccate at the base. Aperture nearly ovate, slightly oblique. 

 Parietal lamella well developed, whitish, very slightly ob- 

 lique, minutely serrate, being set with microscopic thorn-like 

 spines, inclined a little towards the opening. Columella 

 twisted, callous, biplicate. Columellar lamellae parallel, 

 rounded, about equal in size and extending to the margin. Lip 

 thin, unexpanded for the most part, but slightly expanded 

 below, the outer margin slightly arcuate, the columellar mar- 

 gin reflexed, adnate. Length 6.2, diam. 2.8 mm. 



The young are strongly angled at the periphery. The par- 

 ietal lamella is slightly more strongly serrate than in the adult. 

 There is a basal palatal fold as in A. turrit ella, but it is not 

 bifurcate. This fold is set with minute spines, like the parietal 

 lamella. It persists up to the end of the neanic stage, but is 



