660 DR. GWYN JEFFREYS ON THE MOLLUSCA OF THE [Nov. 1/4, 
mon in the north than in the south of England, where it seems to be 
replaced by D. tarentinum. I have not been able to identify D. en- 
talis 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 Hérnes 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. DEwTALIUM 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. tnversum of 
’ Deshayes, a miocene fossil. 
10. DenrTALruM 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, 
pl. ii. f. 23, 24. 
‘Porcupine’ Exp. 1870: Med. St. 50, 50a, Benzert Road, G. 
Tunis, Adventure Bank. 
Distribution. Charente-Inférieure (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. entalis 
and many other species; it is slightly channelled on each side. 
M°Andrew noticed a white variety from Goletta, near Tunis. 
_ 12. DenTatium Fitum, G. B. Sowerby, Jun. 
D. filum, Sow. Thes. Conch. (1866) p. 99, pl. cexxv. f. 45. 
‘Porcupine’ Exp. 1870: Atl. St. Vigo 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. 
Bopy 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- 
