158 TORNATELLINA. 



18. T. LANCEOLATA C. & P. PI. 43, figs. 4, 5, 6. 



Shell cylindrical, elongate, light corneous or vitreous, very 

 glossy, thin, transparent, faintly and irregularly marked with 

 minute growth-striae. Spire with almost lanceolate outlines, 

 summit subacute. Suture impressed, faintly margined be- 

 low. Whorls 5%, slightly convex above, becoming flatter, the 

 last cylindrical, with almost straight outlines. There is a 

 broad shallow depression beginning at about the middle of 

 the last whorl and extending to the outer margin of the aper- 

 ture. Aperture long, narrow, auriform. Parietal lamella 

 large, oblique, slightly arcuate. Columella vertical, strongly 

 twisted. Outer margin of aperture slightly sinuous. Length 

 3.5, diam. 1.3, length of aperture 1.1 mm. 



Oahu: Nuuanu, Tantalus, in very damp localities, under 

 dead leaves and twigs (Cooke). 



This species is more closely related to T. gracilis than to 

 any other Hawaiian species. The shell is, however, thinner 

 and more transparent; the whorls more loosely coiled; the 

 last whorl is longer in proportion to its breadth and with 

 straighter outlines; the aperture is longer and narrower in 

 proportion to its length ; and the spiral depression of the last 

 whorl is not as pronounced as in T. gracilis. 



An embryonic specimen (fig. 5) from Tantalus is less globu- 

 lar than that of T. oblonga and the surface is not as distinctly 

 spirally marked. The parietal lamella is strong, nearly a 

 whole whorl in length. The columella is swollen, with two 

 well-developed oblique folds. 



An example (fig. 4) from Tantalus, at the ananeanic stage, 

 is 2.75 mm. in length and has 5>i whorls. The parietal la- 

 mella is very large, curved, not lobed, with its margin slightly 

 undulating. The columella is triplicate : the upper fold rather 

 strong, the median very strong and the basal nodule fairly 

 well developed. There are two palatal ribs, both of which can 

 be seen in the aperture, the outer low without serrations, the 

 inner strong, with three distinct teeth on its margin. Fig. 6 

 represents the final (ephebic) stage. 



