246 TOBNATELLIDES OF HAWAIIAN ISLANDS. 



Molokai, lias 5^ whorls. The columellar folds are slightly 

 oblique, parallel and the lower is slightly stronger than the 

 upper. An older specimen, with 7 whorls, has the colu- 

 mellar folds nearly equal in height. 



50. T. PRIONOPTYCHIA C. & P., n. sp. PL 52, figs. 3, 4. 



Shell perforate, conic, light brownish-corneous, slightly 

 glossy, under a lens minutely irregularly striate, thin, trans- 

 lucent. Spire conic, with slightly convex outlines, apex sub- 

 acute. Suture simple, subimpressed. Whorls 6, the first em- 

 bryonic increasing very rapidly, the rest increasing slowly and 

 regularly, the last ovate, tapering slightly towards the base, 

 flattened about the umbilicus. Aperture auriform. Parietal 

 lamella low, serrate nearly to its base, the spinif orm serrations 

 oblique and pointing outwards. Columella tumid, furnished 

 with two low linear folds, both of which extend to the margin 

 of the columella. Peristome thin, erect, with the outer mar- 

 gin almost regularly arcuate. Umbilicus rather large, cir^ 

 cular. Length 2.45, diam. 1.3, axis of apert. 0.9, par. lam. 

 0.07, umb. 0.36 mm. 



Oahu : Nuuanu, near the Pali, on dead leaves (Cooke) . Type 

 no. 36241 Bishop Museum, cotype no. 111842 P. A. N. S. 



In an immature specimen with over 5 whorls (fig. 4), the 

 parietal lamella is very strong, about 0.22 mm. in height, the 

 front only is serrate, the serrations being more or less trian- 

 gular and pointing outwards. The columella is furnished with 

 two almost transverse folds, both of which extend nearly to 

 the margin of the columella. The upper is 0.05, the lower 0.13 

 mm. in height. The embryonic whorls are very minutely spir- 

 ally striate. In an immature specimen with less than 5 whorls 

 the parietal lamella is entire. 



The original material of this extremely interesting species 

 was collected in 1904. Since then no additional specimens 

 have been found, although the junior author has collected sev- 

 eral times in the immediate locality, and once especially for 

 this species. It probably is a very local species, limited to the 

 dead leaves under an isolated tree or clump of trees. 



The original and only material came from the second sub- 



