KEPORT ON THE GASTEROPODA. 487 



rounded, very crowded ribs, the parting farrows being shallow and narrow; they run 

 pretty continuously down the spire, but are interrupted by the suture ; they die out slowly 

 on the base. Spirals — below the suture the ribs at their origin are slightly expanded so 

 as to form a kind of collar, and there round the whorls are traces of minute spirals in the 

 furrows of the ribs (but the specimens are somewhat rubbed). Colour white. Spire high, 

 conical, with a slightly convex outline. Apex : the top is somewhat blunt, and from one 

 side of it rises a small dome-shaped tip. Whorls : 7 in all ; they are slightly tumid 

 below and flatly conical above ; the last has a rounded slightly produced base. Suture 

 oblique, a very little impressed. Mouth small, oval, pointed above. Outer lip broken. 

 Inner lip strong and defined on the body, concave out to the point of the short pillar, 

 which has a strong tooth near its top and a slight umbilical depression behind it. 

 H. 0-133 in. B. 0-051. 



The mouth in the specimens of this shell is so much broken that no measurements are possible. 

 There is a single specimen of an Odostomia from Honolulu, 40 fathoms, which may be this species, but 

 is somewhat smaller and has shorter whorls. I have not therefore felt quite able to reckon it as the 

 same, nor yet to part them. 



13. Odostomia (Obelise us) nitidula (A. Adams). 



Syrnola nitidula, A Adams, Ann. and Mag. Nat. Hist., 1860, ser. 3, vol. vi. p. 335. 

 Obeliscus nitididus, A. Adams, Japan. Obeliscina?, Proc. Zool. Soc. Lond., 18G2, p. 232, sp. 5. 



,, „ Dunker, Moll. Mar. Japon., p. 75. 



Pyramidella (Tiberia) nitidula, J. Gwyn Jeffreys, Moll. "Lightning" and "Porcupine," Proc. Zool. 



Soc. Lond., 1884, p. 363, pi. xxvii. fig. 8. 



Station 24. March 25, 1873. Lat. 18° 38' 30" N., long. 65° 5' 30" W. North of 

 Culebra Island, West Indies. 390 fathoms. Pteropod ooze. 



Station 75. July 2, 1873. Lat. 38° 38' N., long. 28° 28' 30" W. Off Fayal, Azores. 

 450 to 500 fathoms. Volcanic mud. 



Habitat. — The Bay of Biscay, from 227 to 1095 fathoms ; the Mediterranean, from 

 207 to 1456 fathoms (Jeffreys); Japan, 25 to 63 fathoms (A. Adams) ; Corea, 40 to 488 

 fathoms (Jeffreys). 



From an examination of Dr Gwyn Jeffreys' specimens of this species, I am satisfied that those of 

 the Challenger only differ in the fulness of their development. 



14. Odostomia (Parthenia) casta (A. Adams). 



Monoptygma casta, A. Adams, Proc. Zool. Soc. Lond., 1851, p. 223. 



„ „ A. Adams in Sowerby's Thes. Conch., voL ii. pt. 15, p. 818, sp. 6, pL clxxii fig. 22, 



and Monoptygma concinna, fig. 34. 

 Myonia concinna, Angas, Port Jackson Moll., Proc. Zool. Soc. Lond., 1867, p. 225, sp. 251. 



