AMASTRA, OAHU. 159 



luster, the last whorl or two dark reddish-brown with some 

 light lines and patches, those above pale yellowish from in- 

 cipient decay of the cuticle. Outlines of the spire are 

 straight, but the individual whorls are very strongly convex. 

 Embryonic whorls smooth ; later whorls with irregular sculp- 

 ture of fine growth-wrinkles. Aperture reddish-brown within, 

 the lip very thin, acute; basal margin well rounded. Colu- 

 inellar margin straight, dilated above, arching over the nar- 

 row umbilicus. Columellar fold thin, very small and strongly 

 oblique. Length 9.8, diarn. 6, aperture 4.9 mm. ; 5 l / 3 whorls. 



Oahu : Wahiawa (Thaanum, type loc.) ; Kawaihulona 

 (Spalding). Type to be placed in the Bishop Museum. 



A. hartmani is a more obese shell with larger umbilicus. 

 A. umbilicata has the whorls but slightly convex, "anfr. 6 

 vix convexiusculi' ' (Pfr.). A. extincta, a larger shell, has 

 similarly low convexity "anfr. 7 vix convexiusculis" (Pfr.). 

 In A. sola the convexity of the whorls is unusually emphatic. 

 Compared with a Molokai specimen of A. umbilicata, this 

 Oahuan shell differs by the more convex whorls, the last whorl 

 wider, not angular around the umbilicus, and the aperture is 

 rounded below, not angular as in umbilicata. 



10. A. EXTINCTA (Pfeiffer). 



"Shell perforate, ovate-turrite, solid, striatulate, chalky. 

 Spire long, tapering upwards, acute. Whorls 7, scarcely con- 

 vex, the last less than one-third the total length, somewhat 

 compressed around the perforation. Aperture slightly ob- 

 lique, rhombic-oval, angular at the base. Columellar fold 

 compressed, ascending almost from the base. Peristome sim- 

 ple, unexpanded, the margins joined by a thick, somewhat 

 nodiferous callus, columellar margin dilated, free. Length 

 16, diam. 7.5 mm.; aperture 5.5 mm. long, 3 wide" (Pfr.). 

 Oahu, subfossil (Frick, in Cuming coll.). 

 ' Achatinella extincta PFR., P. Z. S., 1855, p. 204; Monogr., 

 iv, 550. THWING, Occ. Papers B. P. B. Mus., iii, p. 184; 

 Amastra extincta Pfr., SYKES, Fauna Hawaiiensis, p. 336. 

 L[eptachati'na] hartmani Ncwc., HARTMAN, Proc. A. N. S. 

 Phila., 1888, p. 54, in part; not pi. 1, fig. 12, "type". 



