86 LEPTACHATINA, S.-G. THAANUMIA. 



yellowish sheen, silky, thin, the embryonic whorls with minute 

 spiral striae, the rest closely and regularly costate. Spire 

 conic, apex obtuse. Suture simple, impressed. Whorls 5 l /2, 

 increasing regularly, the embryonic flattened, compressed, 

 shouldered above, the rest somewhat convex, the last rather 

 large, tapering gradually to the base. Aperture rather large, 

 ovate, hardly oblique and slightly diagonal, brownish within. 

 Oolumella narrowly triangular, nearly perpendicular, brown- 

 ish, with a minute, oblique basal fold. Outer lip regularly 

 curved, convex, indistinctly angulate with the base of the 

 columella; columellar margin thin, adnate above, reflexed 

 over the perforation. Umbilicus rather small, subcircular. 

 Length 7.0, diam. 3.7, length of ap. 3.4 mm. 



East Maui: Ulapalakua, Makawao (Baldwin). 



The only representative of this subgenus from Maui. It 

 resembles the species from Oahu and Hawaii rather than those 

 from the nearer island of Molokai. This species has a 

 smaller umbilicus than L. omphalodes Ancey and it is more 

 distinctly costate than L. optabilis. 



111. L. HENSHAWI Sykes. PL 1, figs. 15, 17. 



"Shell ovately pyramidal, rimate, somewhat thin, brown- 

 ish-horny in color, longitudinally well marked with filiform 

 striae, which become weaker towards the base, apex blunt. 

 Whorls 51/2, plano-convex, the protoconch being large and 

 smooth, the others sculptured as mentioned above, the last 

 whorl measuring 4/7 of the entire length of the shell. Suture 

 well marked. Mouth subquadrate, the straight columellar 

 margin being slightly reflected. Plica small and ascending. 

 Length 7.0, diam. 3.6 mm." (Sykes.) 



Hawaii: (Bucholtz) ; Kona, at 1800 feet (Henshaw), Mana 

 fossil (Henshaw), Waimea Plains, near Mana (Thaanum), 

 Hamakua and Kona (Baldwin). 



Leptachatina henshawi SYKES, Journ. of Malac., x, 1903, 

 p. 2, fig. in text. 



"This pretty little shell recalls somewhat in appearance 

 Thaanumia omphalodes Ancey, but lacks the sculpture of 

 the protoconch and the distinct umbilical area. The sculp- 



