660 DR. GWTN JEFFREYS ON THE MOLLTJSCA OF THE [NoV. 14, 



mon in the north than in the south of England, where it seems to be 

 replaced by B. tarentinum, I have not been able to identify D. en- 

 tails as Mediterranean or Adriatic, although the name occurs in 

 nearly every work on the shells of those seas in consequence of 

 D. tarentinum having been mistaken for it. 



Fossil. Pliocene : Red and Belgian Crags. Post-tertiary : Nor- 

 way, Scotland, and N. England ; 4-1360 ft. Not miocene as 

 stated by Homes and others, nor Sicilian (on Tiberi's authority), 

 nor Subapennine as doubtfully indicated by Issel. 



D. pretiosum of Nuttal, and D. indianorum of Philip Carpenter. 



(^ 9. Dentalium subterfissum, Jeffreys. (Plate XLIX. fig. 3.) 



D. subterfissum, Jeffr. in Ann. & Mag. N. H. Feb. 1877, p. 154. 



'Porcupine' Exp. 1869: St. 16, 19, 21. 



Distribution. 'Valorous' Exp. 1450 fms. (fragment). 'Challen- 

 ger' Exp. (off Azores), 1000 fms. 



The peculiar position of the slit is the same as in D. inversum of 

 Deshayes, a miocene fossil. 



!/ 10. Dentalium ensiculus, Jeffreys. (Plate XLIX. fig. 4.) 

 D. ensiculus, Jeffr. in Ann. & Mag. N. H. Feb. 1877, p. 154. 

 'Porcupine' Exp. 1869: St. 19, 40. 1870: Atl. 16, 17, 17a. 

 Distribution. 'Valorous ' Exp., 1450 & 1785 fms. 'Challenger' 



Exp. (off St. Thomas), 470 fms. 



11. Dentalium rubescens, Deshayes. 



D. rubescens, Desh. Anat. et Mon. du genre Dentale, 1825, p. 43, 

 pi. ii. f. 23, 24. 



'Porcupine' Exp. 1870: Med. St. 50, 50ff, Benzert Road, G. 

 Tunis, Adventure Bank. 



Distribution. Charente-Inferieure (Aucapitaine)!, Mediterranean, 

 Adriatic, and Canary I. ; 2-40 fms. 



Fossil. Pliocene : Italy. 



D.fissura of Philippi and others, but not of Lamarck, whose spe- 

 cies is a Grignon fossil. Perhaps also D. translucidum of Deshayes, 

 although he describes the colour as "viridula." 



Perfect specimens have a small terminal pipe or sheath, which is 

 partly enclosed in the shell, but protrudes from it as in D. entails 

 and many other species ; it is shghtly channelled on each side. 

 M'' Andrew noticed a white variety from Goletta, near Tunis. 



t 12. Dentalium filum, G. B. Sowerby, Jun. 



D.filum, Sow. Thes. Conch. (1866) p. 99, pi. ccxxv. f. 45. 



'Porcupine' Exp. 1870: Atl. St. A'^igo B., 13; Med. 55. 



Distribution. Bay of Biscay, Vigo and north of Spain, and various 

 parts of the Mediterranean ; 20-1093 fms. 



Fossil. Pliocene : Calabria and Sicily. 

 ' Body of a whitish colour, except the gills and liver, which are 

 very perceptible through the transparent shell : foot worm-shaped, 

 long and extensile, having the point or extremity arrow-head- 



