818 SCAPHOPODA. [Dentalium. 



1. Dentalium nanum, Hutton, 1873. Plate 49, fig. 17. 



Dentalium nanum., Hutt., C. Tert. M., 1 ; Plioc. M., 73. pi. 8, f. 78 ; Man. 

 Conch. (1), xvii, 9, 210 ; Murdoch and Suter, T.N.Z.I., xxxviii, 303. 



Shell rather small, slightly curved, gradually tapering, with about 

 13 longitudinal ribs. Sculpture : There are 8 to 10 narrow elevated 

 longitudinal ribs at the posterior end, increasing to 10-13 anteriorly 

 where they are much less conspicuous, flatly rounded, and more dis- 

 tant ; in well-preserved specimens there is a secondary longitudinal 

 sculpture, consisting of fine riblets present in the interstices and on 

 the ribs ; there are somewhat irregular undulating transverse growth- 

 lines. Posterior orifice small, circular, with a thick wall. Anterior 

 orifice much larger, circular, peristome thin and sharp. 



Length, 38 mm. ; diameter of aperture, 3 mm. ; diameter of apex, 

 1-5 mm. 



Type, from the Pliocene, in the Dominion Museum, Wellington. 



Hab. Poverty Bay ; Manukau ; off Great Barrier Island, in 

 110 fathoms; Stewart Island, in 18 fathoms (Captain Bollons) ; 

 Snares, in 50 fathoms (Captain Bollons). 



Fossil in the Pliocene. 



2. Dentalium Huttoni, T. W. Kirk, 1880. 



Dentalium Huttoni, T. W. Kirk, T.N.Z.I., xii, 1879 (1880), 306; 

 A.M.N.H. (5), vi, 1880, 15 ; Man. Conch. (1), xvii, 71 ; Murdoch and 

 Suter, T.N.Z.I., xxxviii, 303. 



Shell white, lustrous, small, curved, rapidly tapering, longitudi- 

 nally ribbed. Sculpture consisting of somewhat unequal longitudinal 

 riblets, about 18 at the anterior end, but there is no secondary longi- 

 tudinal sculpture ; transverse growth-lines distinct. Colour white. 

 Posterior orifice small, circular, -simple. Aperture circular, with a thin 

 and sharp lip. 



Length, 15-75 mm. ; diameter of aperture, 2-5 mm. 



Type in the Dominion Museum, Wellington. 



Hob. Off Great Barrier Island, in 110 fathoms ; north of the 

 Auckland Islands, in 85 fathoms (Edgar R. Waite). 



Remarks. The type is from the stomach of a trumpeter (Latris 

 hecateia). There are three specimens, but two are no doubt D. nanum. 



Subgen. 2. FISSIDENTALIUM, P. Fischer, 1885. 



Fissidentalium, P. Fischer, Man. de Conch., 1885, 894. Type : Drntalium 

 ergasticum, Fischer. 



Shell large and solid, sculptured with many longitudinal riblets, 

 the apex typically with a long slit, but often simple, sometimes with 

 a slit divided into a series of fissures. 



Mainly deep-water species, of all temperate and tropical seas, 

 distinguished chiefly by the large size and solidity of the shell with 



