DENTALIUM-LJEVIDENTALIUM. 101 



D. rubescens Deshayes, which is less curved in front and more curved 

 near the tip, is smaller, deeper colored, and has a very long narrow 

 posterior slit when perfect, quite different from that of callipeplum. 

 The specimen figured is young ; better specimens, from which the 

 description was drawn up, were dredged by the Fish Commission. 

 The striation on the tip is so faint as to be very difficult to see, while 

 the surface is so brilliant as not easily to be scrutinized. (Dall). 

 It has the oily luster of D. longitrorsum. 



D. ENSIFORME Chenu. PI. 15, fig. 37. 



Shell arcuate, smooth, white, the aperture oblique. (Ghenu). 



Antilles. 



D. ensiforme CHENU, Illustr, Conchyl., i, p. 3, pi. 6, f. 18. 



Deshayes remarks : Very near inversum in curvature and size, 

 but that differs in the slit ; narrower than lacteum. Length 24, diam. 

 at aperture slightly exceeding 1*5 mill. 



D. SUBTORQUATUM Fischer. 



Shell white, thin, narrow, shining, cylindrical, slightly curved. 

 Encircled at the apex with minute, close, somewhat raised trans- 

 verse striae. Apex entire. No longitudinal striation. Length 22, 

 diam. 2 mill. (Fischer). 



Suez (Gaudry). 



D. subtorquatum FISCHER, Journ. de Conch., xix [(3) xi], pp. 218, 

 212 (1871). 



D. ANULOSUM Brazier. 



Shell thin, transparent, tapering, slightly curved, marked by in- 

 cised circular lines from the apex to the centre, and from that to the 

 base quite smooth, apex thickened, perforated, perforation entire, 

 aperture circular. Length 7 lines [14 mill.] (Braz.*). 



Princess Charlotte Bay, northeast Australia, 13 fathoms, sandy 

 bottom (Chevert Exped.). 



Dentalium anulosum BRAZIER, Proc. Linn. Soc. N. S. Wales, ii, p. 

 58 (1877). 



The upper part of this beautiful, thin, transparent shell has a 

 ringed appearance like a trachea. Allied to Dentalium politum 

 Linn., that species being distinguished by the incised lines that di- 

 vide its whole length (Braz.). 



