HAWAIIAN NESOPUPAE. 281 



specimens carefully compared with the type but with better 

 preserved surfaces, the third and fourth whorls are distinctly 

 costate ; on the last whorl the costae are at first well developed 

 near the suture, becoming weaker below ; the interstices are 

 very minutely striate with lines of growth. The base is com- 

 pressed and prominent. There is a narrow, rather deep con- 

 centric sulcus on the back of the last whorl, just above the 

 lower palatal fold, but no twisted sulcus just in back and 

 parallel with the peristome, and merely a flattening over the 

 upper palatal fold. In the holotype the costs? are about .055 

 mm. apart on penultimate whorl and the shell has the follow- 

 ing measurements: length 1.53, diam. 0.95, greatest length of 

 apert. 0.61 mm. There are about by whorls and the outer 

 margin of the aperture is not flattened. This is not the case 

 in most of the adults examined ; for nearly all the fully adult 

 specimens have 5i/ 2 whorls, and the outer margin of the aper- 

 ture is slightly flattened. 



The typical form is distributed over the whole Koolau 

 Mountain range of Oahu. It is exceedingly abundant, if one 

 has the patience to look for these minute forms, and can 

 nearly always be found on the dead leaves of ieie (Freycinetia) 

 wherever this plant ocelli's. It is occasionally found on other 

 dead leaves, but rarely on stones. In one or two isolated cases 

 the junior author has found typical specimens under moss on 

 trunks of living trees. A single example of the typical form 

 from the Waianae Mts. is in the Bishop Museum collection. 



Occurring with typical examples are a few slightly larger 

 specimens from upper Kaliuwaa and Kaipapau, Oahu. They 

 differ only in that the outline is slightly more cylindrical and 

 the shells are slightly longer. One with 5}/o whorls measures: 

 Length 1.71, diam. 0.92, apert. 0.6 mm. in greatest length. 



2. NESOPUPA WAIANAENSIS C. & P., n. sp. PI. 27, figs. 4, 5, 6. 



The shell is minute, perforate (umbilicus minute, deep, semi- 

 circular in outline), ovately conic, snuff-brown, distinctly cos- 

 tulate except on the embryonic whorls, shining, quite thin, 

 somewhat translucent. Spire with convex outlines, and 

 rounded apex ; individual whorls convex, separated by a rather 



