TORNATELLIDES OF HAWAIIAN ISLANDS. 243 



48. T. LEPTOSPIRA C. & P., 11. sp. PI. 51, figs. 11, 12, 13. 



Shell perforate, narrowly elongate-ovate, brownish-corne- 

 ous, glossy, under a lens very minutely striate, thin, translu- 

 cent. Spire narrowly turrited, with slightlj' convex outlines, 

 apex blunt. Suture slightly impressed, simple. Whorls 5%, 

 the embryonic increasing very rapidly, the rest increasing 

 slowly and regularly, convex, the last slightly swollen, ob- 

 liquely truncate at the base. Aperture rather large, auri- 

 form. Parietal lamella low. Columella unarmed, narrow. 

 Peristome thin, erect, with its outer margin regularly curved. 

 Umbilicus rather large. Length 2.1, diam. 1.1, axis of apert. 

 0.85, par. lam. 0.03, umb. 0.3 mm. 



Oahu: Nuuanu near the Pali, on the stems of a grass 

 (Agrostis variabilis). Type no. 36268 Bishop Museum, co- 

 types no. 111833 P. A. N. S. 



Most nearly related to T. virgula of East Maui. From this 

 species it differs in size, fewer whorls, smaller parietal lamella, 

 etc. It is undoubtedly one of the smallest species of Torna- 

 tellides inhabiting the Hawaiian Islands. It is very common 

 on the stems of the bunch grass near the Nuuanu Pali. T. 

 brunnea is found on the same plants but usually occurs on the 

 leaves. 



In an immature specimen with 4^ whorls the parietal la- 

 mella is large and oblique, 0.18 mm. in height. The colu- 

 mellar folds are strong and nearly parallel, the upper is 0.07, 

 the lower 0.11 mm. in height. The embryonic whorls are regu- 

 larly spirally striate. The striae are fine and widely spaced 

 (fig. 13). 



An embryonic specimen is almost globose. It has a narrow, 

 cleft-like perforation. The columella is thickened longitudi- 

 nally, a little back of the margin, forming a narrow longitu- 

 dinal fold, which is bidentate. The parietal lamella is moder- 

 ately developed. The surface of the shell is very minutely 

 clathratulate (fig. 11). 



Group of T. tercbra. 



Shells of 6-81/2 compressed whorls, the last slightly flattened 

 about the margin of the umbilicus. The parietal lamella is 

 serrate or bears one or more acute projections. 



