170 TORNATELLINA. 



Bonin Islands: Imoto-jima (type loe.), and Haha-jima, 

 Ogasawara. Types no. 86479 A. N. S. P. 



Tornatellina monodonta PILSBRY and HIRASE, Nautilus, 

 xviii, May, 1904, p. 6. 



This form is distinguished at once from others described 

 from Ogasawara-jima and the islands of Izu by the absence of 

 a parietal lamella. T. rucuana is not so smooth, and has a low 

 parietal lamella. 



The columellar fold is distinctly if rather minutely doubled 

 (fig. 2), especially in immature .specimens, though some trace 

 of the same structure may be seen in adults. Fig. 1 repre- 

 sents the type. Fig. 2 is a specimen from Haha-jima, viewed 

 obliquely from below. 



26. T. RUCUANA Pilsbry & Hirase. PL 37, figs. 4, 5. 



The shell is imperforate, oblong-conic, thin, brownish-cor- 

 neous, the early whorls brown; smoothish, weakly marked 

 with growth-lines, somewhat glossy. Spire conic, the apex 

 obtuse. Whorls 4^, convex. Aperture oblique, ovate ; outer 

 lip thin and simple. Columella rather strongly twisted spir- 

 ally, in immature specimens indistinctly doubled (fig. 5), a 

 low fold appearing about the middle and very obliquely run- 

 ning downward. In adult shells this is not noticeable. Pari- 

 etal lamella small and low, about a half- whorl long. Length 

 3.3, diam. 1.9, length of aperture 1.4 mm. 



Loochoo (Eyukyu) Islands: Kerama-jima (Hirase). Type 

 110. 89891 A. N. S. P. 



Tornatellina rucuana P. & H., Proc. A. N. S. Phila., Ivii, p. 

 718 (Dec. 8, 1905). 



This species resembles T. monodonta, from which it differs 

 chiefly by the possession of a low but well-developed parietal 

 lamella. It is also less conic, a little more oval in shape. Half- 

 grown examples are like the adult stage in this respect. The 

 parietal lamella is smaller than in T. ogasawarana or T. na- 

 kodai. 



27. T. NAKADAI P. &.C., n. sp. PL 37, figs. 8, 9, 10. 



The shell is slender, pale brownish-yellow, nearly smooth, 



