AMASTRA, OAHU. 191 



solid. Outlines of the spire are nearly straight below, be- 

 coming a little concave near the summit ; whorls slightly con- 

 vex, short ; embryonic 2% are dull purplish, very finely, reg- 

 ularly striate where unworn; subsequent whorls irregularly 

 wrinkle-striate, the cuticle at first light olive, on the last two 

 whorls olive-brown ; rather glossy ; where worn away showing 

 a dull gray and purplish-brown calcareous layer. The aper- 

 ture is small, slightly oblique, dull purplish-gray within, paler 

 and just perceptibly thickened near the lip. Columella short, 

 thick, whitish, bearing a subhorizontal lamella. Parietal callus 

 very tihick, its edge forming a ledge connecting the lip-ends. 

 Length 15.5, diam. 8.6, aperture 6.9 mm. ; whorls 7. 



Oahu: Kahauiki (D. Thaanum). Type to be deposited in 

 the Bishop Museum. 



This species is related to A. crassilabrum, from which it 

 differs by its color, the less attenuate spire, much less thick- 

 ened lip, and by the thick parietal callus of old individuals. 

 Kahauiki is a short valley between Kalihi and Moanalua. 



Section AMASTRELLA Sykes. 

 See p. 151. 



Series of A. inflata. 



Amastrae with finely striate or nearly smooth embryonic 

 whorls (sometimes irregularly costate in A. tristis) ; the junc- 

 tion of columellar and basal margins of the aperture rounded 

 (not subangular or spout-like). The shell is more or less 

 completely covered with a dull or dark, in part transient, 

 sometimes very thin cuticle, under which it is not banded. 



These shells agree well with the typical Kauaian Amas- 

 trellse except in the development of a more or less conspicuous 

 dark outer layer of cuticle, a character showing an advance 

 beyond typical Amastrella. This cuticle is not mottled or fig- 

 ured with angular streaks, as it is in typical Amastra. The 

 group differs from Metamastra- by the more widely rounded 

 margin below the columellar lamella, which is smaller and 

 less horizontal. 



The inflata series contains the least specialized of the 



