1244 TOBNATELLIDES OF HAWAIIAN ISLANDS. 



This group is distributed on all the islands. Most of the 

 species are found only on dead leaves and twigs. 



a. Parietal lamella with fine spine-like serrations. 



b. Adult shells with less than 7 whorls, and with the 

 diameter more than 50 per cent of the length. 



c. Parietal lamella of adult shells moderately de- 

 veloped, more than 0.1 mm. in height, outlines 

 of spire convex. 



d. Adult shells more than 2.5 mm. in length ; 

 parietal lamella serrate, the incisions 

 about ys- l /2 its height. 



T. forbesi, no. 52. 



d l . Adult shells less than 2.5 nun. in length ; 

 parietal lamella serrate nearly to its base. 



T. f. nanus, no. 52o-. 



c 1 . Parietal lamella of adult shells low, less than 



than 0.1 mm. in height ; outlines of spire conic. 



d. Diameter contained about 1.9 times in 



the length. T. prionoptychia, no. 50. 



d 1 . Diameter contained about 1.6 times in 



the length. T. serrarius, no. 51. 



& 1 . Adult shells with more than 7 whorls, and with the 



diameter less than 40 per cent, of the length. 



T. terebra, no. 49. 



a 1 . Parietal lamella bearing' a scythe-like process, and without 

 spine-like serrations. T. drepanophora, no. 53. 



49. T. TEREBRA (Ancey). PL 52, figs. 1, 2. 



"Shell elongate, terebriform, thin, pellucid, light-corneous, 

 under the lens lightly and closely impressed with growth 

 lines, minutely perforate. Spire much produced, regularly, 

 couically tapering, the apex minute. Whorls 7 to 7 1 / 4, closely 

 coiled, a little convex. Suture somewhat impressed. Aper- 

 ture small, somewhat oblique, truncate-oval, with a rather 

 small and serrate parietal lamella. Columella provided with 

 two folds, scarcely visible in adult shells. Peristome acute, 

 unexpanded, the columcllar margin minutely dilated and ex- 

 panded. Last whorl short, rounded, somewhat saccate. 

 Length 2.66, diam. 1.0. alt, apert. 0.75 mm." (Ancey}. 



