PRONESOPUPA MOLOKAIENSIS The shell is very like that of P. frondicola but slightly smaller, darker colored and narrower in proportion to its length. The aperture is vertical, not slightly diagonal. The surface of the two lower whorls is covered by somewhat coarser costulation, the riblets about 0.07 mm. apart. There is a minute, deeply situated swelling near the middle of the inner face of the columella, as in a few of the specimens of P. frondicola. Length 1.96, diam. 1.04, aperture (diag.) 0.73 mm. Molokai Kawela, at about 3,500 ft. (type loc.), and Waikolu, about the same elevation; on the leaves of low plants (Cooke). Holotype 41806 Bishop Museum. Only two examples of this species are known at present, one from each of the localities mentioned above. It is with some hesitancy that we separate the above species from P. frondicola of East Maui, under which it might not improperly be placed as a variety. The coarser and more distant costæ, as well as its geographical distribution, are the most impor- tant reasons for considering them specifically distinct.