REPORT ON THE GASTEROPODA. 339 



irregularly semicircular, angulated above, and ending in a distinct open canal below. 

 Outer lip excessively thin, slightly patulous below, but not at all above ; it leaves the 

 body at a right angle, and advances across the sinus-area in a perfectly straight line ; it 

 is angulated at the keel, from which point it curves very regularly, till towards the edge 

 of the canal it becomes concave and finally straight ; round the front of the canal it is not 

 in the least patulous : its edge forms a semicircular curve with a high shoulder, between 

 which and the body lies the large, broad, open, rounded sinus. Inner lip, which, though 

 very narrow, is continued to the point of the pillar, is cut into the substance of the shell, 

 and is defined by a slight raised margin beyond it ; the line across the body is very short, 

 and joins the pillar at a very obtuse angle. The pillar is very long and straight, and is 

 cut off in front with a very gradually oblique, thin, twisted edge. H. 1*04 in. B. - 52. 

 Penultimate whorl, height 0-2. Mouth, height 0"59, breadth 0"3. 



This is a species of the most singular beauty and delicacy, like nothing known to me. 



68. Pleurotoma {Mangelia) nitens, Hinds. 



Clavatida nitens, Hinds, Voy. " Sulphur," p. 20, No. 67, pi. vi. fig. 17. 



Pleurotoma nitens, Reeve, Conch. Icon., vol. i. pi. xxii. fig. 189. 



Drillia (Clavatida) nitens, Brazier, " Chevert " Exped. Shells, Proc. Linn. Soc. New South Wales, 



vol. i. p. 154. 

 Mangilia nitens, Tryon, Manual, vol. vi. p. 253, pi. xx. fig. 2. 



July 29, 1874. Levuka, Fiji. 12 fathoms. 



Habitat. — New Guinea, Straits of Macassar and Malacca, from 7 to 22 fathoms (Hinds), 

 North-east Australia and Torres Strait (Brazier). 



69. Pleurotoma {Mangelia) subtilis, Watson (PI. XXIII. fig. 4). 



Pleurotoma (Mangelia) subtilis, "Watson, Prelim. Report, pt. 9, Journ. Linn. Soc. Lond., vol. xv. p. 430. 



Station 122. September 10, 1873. Lat. 9° 5' S., long. 34° 50' W. Off Pernambuco. 

 350 fathoms. Eed mud. 



Shell. — Very small, conical, sharp-tipped, with a lop-sided base, subscalar, ribbed, and 

 with spiral threads ; there is a strong labral varix, with a small, deep, round sinus. 

 Sculpture : Longitudinals — there are on the last whorl about thirteen rounded, rather 

 weak, slightly oblique longitudinal ribs, which extend to the snout ; on the fifth and sixth 

 whorls they are fewer, but rather stronger ; on the fourth whorl they are lamellar ; they 

 are parted by shallow open furrows of fully two-thirds their breadth. The whole surface 

 is covered with microscopic but coarse hair-like lines of growth. Spirals — there are 25 to 

 30 close-set, flatly rounded, alternatingly stronger and weaker spiral threads, of which 

 those on the shoulder and base of the last whorl are the weakest ; those (twelve in 



