LEPTACHATINA, S.-G. THAANUMIA. 87 



ture is similar in nature to that of L. tenebrosa, Pease, of 

 Kauai, etc." (Sykes.) 



L. tenuicostata Pease, is somewhat closely related to this 

 species. The latter is, however perforate; the outlines of 

 the spire and the whorls are more convex; the columellar 

 fold is stronger and approaches the outer face of the colu- 

 mella, etc. 



Mr. Thaanum kindly lent me a few specimens of this species 

 from the original lot collected by Dr. Henshaw. All the 

 specimens had the characteristic blunt apex; in a few the 

 spiral lines of the embryonic whorls were made out with a 

 strong lens. 



112. L. MORBIDA n. sp. PL 13, fig. 12. 



The shell is minutely perforate (sometimes imperf orate), 

 conic, dark brown, hardly glossy, rather solid, not diaph- 

 anous, distinctly costate (especially on the neanic whorls), 

 the embryonic whorls smooth. Spire conic, apex somewhat 

 obtuse. Suture very slightly impressed, crenulate. Whorls 

 6, regularly increasing, the embryonic flattened, slightly shoul- 

 dered above, with a rather distinct suture, the rest slightly 

 convex, the last rotundate, tapering to the base. Aperture 

 large, ovate, purplish brown within, hardly oblique, slightly 

 diagonal. Columella nearly straight, with a thick acute 

 callus along its face; columellar fold median, small, blunt. 

 Outer lip regularly convex, thickened within, white; colu- 

 mellar margin slightly thickened, reflexed, adnate above. 

 Umbilicus minute, oval. Length 9.0, diam. 4.7, length of 

 ap. 4.0 mm. 



Molokai: Puu Kolekole, under logs in open country 

 (Thaanum). 



This species is provisionally placed in the subgenus Thaa- 

 numia. It differs from the other species of this subgenus, by 

 not having spirally striate embryonic whorls. These are, 

 however, slightly flattened, compressed and have the rather 

 distinct suture characteristic of this subgenus. 



The nearest relative to this species, from Molokai, is L. 

 (Thaanumia) Thaanumi. The latter is, however, smaller, 



