320 HAWAIIAN NESOPUPAE. 



is rather short, thickened and low; the two palatal are short, 

 nearly parallel, the lower nearly twice as high and long as the 

 upper. An average specimen measures : length 2.1, diain. 1.4, 

 greatest length apert. 0.86 mm. At a somewhat higher ele- 

 vation the shells are slightly larger. One such measures: 

 length 2.6, diam. 1.55, apert. 1.04 mm. 



On the same ridge, but nearer the sea and at a slightly 

 lower station, the shells are much smaller. Among thirty 

 examples taken at random, 12 had the five normal lamellae 

 in the aperture; in 18 there was in addition a more or less 

 minute basal fold. In this small race of kauaiensis the speci- 

 mens at first glance have the appearance of typical newcombi. 

 They are most easily recognized by the less expanded and 

 more heavily thickened peristome and the lower and less mem- 

 branous ribs, of which there are about 30 on the last whorl. 

 A specimen of this small race (p. 309, f. 9) measures: length 

 1.63, diam. 1.16, aperture 0.73 mm. ; 4% whorls. This race is 

 widely distributed on Kauai, in rather damp situations on 

 rocks. 



18. NESOPUPA SINGULARS C. & P., n. sp. PI. 29, fig. 8. 



The shell is minute, perforate (perforation very minute, 

 nearly circular) ovately conic, with a short base, clay color, 

 thin, translucent, rather dull, the surface rather closely ribbed- 

 striate, a few of the striae, especially on the back of the last 

 whorl (rather distantly and more or less evenly spaced) are 

 more strongly developed and furnished with membranous 

 edges; under a microscope the whole surface covered with 

 very minute wrinkles. Spire with convex outlines tapering 

 gradually to the semi-globular apex; individual whorls very 

 convex, separated by a deep suture. Whorls 4% ; the em- 

 bryonic minutely granulose, the granules more or less ar- 

 ranged in transverse rows, the striae beginning gradually 

 at about 1% whorls. The last whorl is sub-saccate, rounded 

 about the umbilicus, the last % nearly straight. Aperture 

 hardly oblique, nearly perpendicular, almost a complete circle, 

 lip-insertions nearly united, connected by a rather thick, 

 short white callus. Angular lamella usually absent, sometimes 



