490 THE VOYAGE OF H.M.S. CHALLENGER. 



19. Odostoraia (Turbonilla) philomelcB, n. sp. (PI. XXXII. fig. 2). 



Station 135c. October 17, 1873. Lat. 37° 25' 30" S., long. 12° 28' 30" W. Off 

 Nightingale Island, Tristan da Cunha. 100 to 150 fathoms. 



Shell. — Thin, high and narrow, conical, with a dull surface, a largish turned-over 

 sinistral tip, convex whorls, an impressed suture, a rounded somewhat produced base, and 

 a longish narrowly oval mouth. Sculpture : Longitudinals — besides fine and faint lines 

 of growth, there are about 25 narrow rounded ribs, which are sinistrally oblique, and not 

 flexuous; they are parted by rounded furrows of about half their breadth; 1 they stop 

 abruptly at the edge of the base. Spirals — none whatever. Colour dull transparent 

 white. Spire high, narrow, and conical. Apex narrows gradually, the extreme tip is small ; 

 it consists of 1^ whorls, which are sinistral, discoidal, and turned more than one-fourth over ; 

 this tip rising somewhat prominently forms a small rounded top. Whorls 5-g, exclusive 

 of the embryonic tip, of slow and regular increase, a little flatly convex ; the last has a 

 perfectly rounded slightly produced base. Suture strong, openly impressed, oblique. 

 Mouth a long narrow oval, slightly pointed (but without any narrowing) above, and at 

 the point of the pillar. Outer lip thin, slightly patulous in front, and pointed in front 

 of the pillar. Inner lip unrecognisable on the body, thin and slightly concave on the 

 pillar, with no umbilical furrow whatever. H. 0'117 in. B. 0"039. Mouth, height '033, 

 breadth 0"024. 



This species has a slight general resemblance to Odostomia indistincta, Mont., with a much deeper 

 suture, and with whorls more oblique and more rounded. It is still more like a very refined 

 Odostomia clathrata, Jeffr./but is finer, smaller, with more delicate and straighter ribs and no spirals ; 

 the suture is slighter, being shallower and opener, and there is no umbilicus. In sculpture it is not 

 unlike Odostomia Levis, C. B. Ad., from Jamaica, but the form is quite different. 



20. Odostomia (Turbonilla) homceotata? n. sp. (PI. XXXII. fig. 3). 

 September 8, 1874. Flinders Passage, Cape York. 7 fathoms. 



Shell. — Strongish, high, and narrow, conical, with a dull surface, a small abrupt top, a 

 turned-over sinistral tip, barely convex whorls, a hardly impressed suture, a short rounded 

 base, and a small oval mouth. Sculpture: Longitudinals — there are about 20 rather 

 strong and high round straight but oblique ribs on each whorl ; they cease not quite sud- 

 denly on the edge of the base ; they are parted by deepish rounded furrows of about the 

 same breadth as themselves ; they begin on the first regular whorl ; in the suture they 

 are feeble. Spirals — there is some faint appearance of one or two very obsolete fiat 

 threads just round the edge of the base. Colour something between dull horny and 



1 The figure entirely misrepresents this feature. 

 2 o/io/oVaros, very like; resembling such forms as Odostomia indistincta and Odostomia interstinda. 



