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



7. Odostomia corpulenta, n. sp. (PL XXXI. fig. 3). 



Station 187. September 9, 1874. Lat. 10° 36' S., long. 141° 55' E. Cape York, 

 North-east Australia. 6 fathoms. Coral mud. 



Shell. — Not very strong, translucent, smooth and glossy, strongly toothed, ovate, with 

 a high conical subscalar sharp-pointed spire, a produced base, and a smallish pear-shaped 

 mouth. Sculpture: there are weak, rounded lines of growth, and very obscure minute 

 superficial close-set microscopic spirals. Colour white, horny, glossy. Spire rather high, 

 with a convexly conical outline ; the subscalar rise is caused by a very minute but rec- 

 tangular projection of each succeeding whorl immediately below the suture. Apex : the top is 

 small, and from it rises on one side the three-quarter reversed tip, the extreme point of which 

 is hidden. Whorls 6 J in all ; very slightly convexly conical, of regular but rather rapid 

 increase ; they terminate with a sharp rectangular abruptness at the suture. Suture almost, 

 but not really channelled, very oblique. Mouth small, pear-shaped, being sharply pointed 

 above, rounded and very patulous in front. Outer Up thin and sharp, straight 'above and 

 a little inflected, acutely rounded and very patulous on the base. Inner Up thin, but 

 defined and a little sj)read out on the body ; from the corner of the outer lip it runs 

 obliquely but directly to the point of the pillar, round whose top twists a small furrow, 

 which, from behind the pillar-lip, runs in above the strong and but little oblique tooth. 

 H. 0-194 in. B. 0-083. Mouth, height 0'082, breadth 0*049. 



This species in form considerably resembles Odostomia eburnea, Metcalfe, from South Australia, 

 but is larger, and the columellar tooth is not high up as in that species. 



8. Odostomia oxia, 1 n. sp. (PI. XXXI. fig. 4). 



September 8, 1874. Flinders Passage, Cape York, North-east Australia. 7 fathoms. 



Shell. — Small, narrow, conical, few-whorled, with a well-marked suture, a longish last 

 whorl, and an upturned and immersed tip. Sculpture : there are many feeble lines of 

 growth and some very faint spirals. Colour white. Spire high and narrow. Apex small, 

 consisting of a whorl and a half, obliquely but very shortly drawn out, and turned over on 

 one side. Whorls 5 in all ; they are barely convex on the side, but are slightly con- 

 stricted at top and bottom. Suture distinct, being a little impressed. Mouth small, 

 elongately pear-shaped. Outer lip almost straight above ; on the base obliquely rounded 

 and patulous ; pointed at the tip of the pillar. Inner Up rather thin on the body, obtusely 

 angulated at the top of the pillar, where there is a strongish tooth ; the pillar is concave, 

 with a slightly reverted edge, behind which is a small furrow and umbilical chink. 

 H. 0-08 in. B. 0'038. Mouth, height 0'031, breadth 0'02. 



This species somewhat resembles an elongated form of Odostomia acuta," Jeffr., with fewer whorls 

 and a much stronger shell. 



o;i;, sharp. 2 Hence the name. 



