AMASTRA, LANAI. 233 



d. Yellow under blackish cuticle; last 



whorl strongly convex. 



A. rubristoma, no. 61. 

 d\ Whitish under blackish cuticle; last 



whorl rather compressed; length 20 to 



23, diam. 11 mm. A. biplicata, no. 62. 

 d 2 . Diameter usually more than half the 



length ; length 14 to 20 mm. 



A. durandi, no. 63. 

 d 3 . More slender, smaller, diam. less than 



half the length. A. moesta, no. 64. 



Section HETERAMASTRA Pilsbry. 

 55. A. PRATERNA Sykes. PI. 49, fig. 9 ; pi. 17, tigs. 11, 14. 



" Shell sinistral, ovate turriform, thin; suture impressed; 

 whorls 61/2 to 7, a little convex, longitudinally striated, cov- 

 ered mth a brown or blackish-corneous epidermis. Aperture 

 ovate, moderate; peristome unexpanded, acute; lamina mod- 

 erate. Length 10, diam. 5.5 mm. " (Sykes'). 



Lanai: Mountains 'behind Koela (Perkins). 



Amastra fraterna SYKES, Proc. Malac. Soc. London ii, pt. 

 3, p. 129, October, 1896. Amastra (Laminella) fraterna 

 SYKES Fauna Hawaiiensis, p. 349, pi. 11, f. 23. 



Mr. Sykes 's original figure is copied in our pi. 49, fig. 9. 

 The shell is more inflated than any of the soror group of Maui. 

 It is entirely clothed with a thin, dark-brown or black cuticle, 

 worn off in front of the aperture exposing the purple-brown 

 under-color. The typical form has a nearly straight-sided 

 spire and is composed of 6% to 7 whorls (pi. 49, fig. 9). 



A somewhat different form was collected by Mr. D. Thaa- 

 nuin, exact locality not given. It has fewer whorls and a con- 

 cave-sided spire (pi. 17, figs. 11, 14). The embryonic whorls 

 are very beautifully costellate, the riblets being narrow. They 

 are represented as much too wide in pi. 17, fig. 14. The whorls 

 are convex, the last one inflated ; outlines of the spire concave. 

 The columellar lamella is rather small, becoming larger within. 

 The figures on plate 17 are from specimens collected by Mr. 



