194 AMASTRA, OAHU. 



chiefly on account of the well-developed outer cuticle. If this 

 view be correct, it must be viewed as a recent immigrant in 

 the Waianae range. 



Herr Borcherding is hopelessly wrong in lumping rub ens 

 with mastersi Nc. His inference that the species ranges over 

 three islands is consequently baseless (see Zoologica, xix, Heft 

 48 ii, p. 117). The embryonic whorls are totally diverse in 

 the two species. 



35a. A. rub ens corneifortnis n. subs p. PI. 31, figs. 17 (nat. 



size) ,18. 



The shell is subperforate, ovate-turrite, rather solid, some- 

 what glossy. Spire with slightly convex outlines in the lower 

 part, straightened or a trifle contracted near the summit. 

 Embryonic whorls brown, somewhat worn, but apparently 

 'with a weak sculpture of regular, arcuate striae. Following 

 whorls marked with growth-wrinkles, at first 'brown, whitish 

 below the suture, changing on the penultimate whorl, becom- 

 ing on the last whorl whitish, faintly brown-tinted. On the 

 last half- whorl this ground- tint is largely covered by a smooth, 

 dense, blackish-brown outer cuticle, in part deciduous. Aper- 

 ture whitish within; lip thin. Columella straight, its edge 

 abruptly triangularly dilated above; bearing a thin lamella 

 in the middle. Length 16.5, diam. 8.6, aperture 7.1 mm.; 6% 

 whorls. 



Oahu : Waianae. Type no. 1753 C. M. Cooke coll. 



Much more slender than A. rub ens, and having much the 

 general appearance of A. cornea. 



35&. A. nibcns castauea n. subsp. PI. 32, fig. 18. 



A reddish-chestnut cuticle covers the whole surface, even 

 the spire. It is yellowish below the suture and black behind 

 the lip. The spire is a little attenuated near the summit. 

 The interior has a faint roseate tint, nearly white. Length 

 17, diam. 9.5 mm. 



Waianae. Types no. 1761 Cooke coll. ; co-type no. 104690 

 A. N. S. P. 



In the Cooke collection there is a series of stunted or de- 



