LEPTACHATINA, GROUP N. 67 



Gulick; it is inconspicuously costulate below the suture, the 

 sculpture gradually fading out, until the last whorl hardly 

 shows any marking beyond the lines of growth. There is a 

 faint spiral line just below the suture." (Sykes.) 



I have referred to this species three lots of shells in Mr. 

 Thaanum's collection. The shells do not agree with Mr. 

 Sykes' measurements but they have the other characteristics 

 fairly well represented. 



A well developed specimen, with 10%' whorls has the fol- 

 lowing measurements : length 9.3, diam. 3.0, 1. of ap. 2.8 mm. 

 If these shells do not belong to L. supracostata they must be 

 an undescribed species. Fig. 19 is a copy of that of Mr. 

 Sykes. 



88. L. LANAIENSIS n. sp. PI. 12, figs. 2, 3. 



The shell is minutely perforate, elongate, light corneous, 

 thin, subdiaphanous, of a silky lustre, finely and closely cos- 

 tate (except the embryonic whorls), the costae thin. Spire 

 elongately conic, slightly attenuate above, apex obtuse. 

 Suture simple, slightly impressed. Whorls S 1 /?, convex, 

 closely coiled, the last subcylindrical, tapering to the base. 

 Aperture narrowly ovate, acute at both ends, very slightly 

 oblique and slightly diagonal. Columella nearly straight, 

 slightly callous along its face, with a rather small oblique 

 fold extending to the margin. Outer lip very slightly thick- 

 ened within, regularly curved to the base of the columella; 

 columellar margin thin, adnate for about one-half of its length, 

 both margins united by a thin transparent parietal callus. 

 Umbilicus minute. Length 8.0, diam. 3.2, length of ap. 3.0 

 mm. 



Lanai ( Thaanum) . 



This species is much more abundant than L. impressa, 

 Sykes to which it is closely related. It differs in being broader 

 in proportion to its length, thinner, with finer and closer 

 striae, the whorls are more convex, and it is always minutely 

 perforate. 



There are two color forms besides the one noted above : one 

 a brownish corneous and the other light corneous with a dark 



