454 DENTALIAD^i. 



The animal is minutely described by Mr. Clarke in the 

 valuable paper already cited, and the features we have 

 mentioned in our notice of the characters of the genus are 

 taken from his account of his species. It differs from the 

 preceding in being of less slender form, of a yellowish white 

 colour, instead of pure white, and possessing dark greenish 

 brown, elongated, suboval branchiae. 



This tooth-shell may be regarded as a member of the 

 southern regions of the British Fauna, and, though not 

 rare in many places, is on the whole a much more uncom- 

 mon species than the last. It inhabits the sandy shores of 

 Kent, Sussex, and Dorset (S.H.) ; " the coralline zones 

 of the South Devon coasts, five or six miles from land, in 

 twelve to fifteen fathoms water" (Clark); Torbay (Alder); 

 Ilfracombe (Miss Alder). East side of Lundy Island in 

 from seven to twenty-five fathoms (M' Andrew). Mr. W. 

 Thompson, in his " Report on the Irish Fauna," indicates 

 its presence in both east and west shores of Ireland ; absent 

 from the northern coasts. 



It ranges to the Mediterranean ; it is found fossil in the 

 pleistocene tertiary at Bridlington. 



The D. gadus of Montagu, and the siibulatum of the British 

 Marine Conchology, are species of Ditrupa, and consequently 

 belong to the Aunelides ; Turton's type of D. clausum is merely 

 a portion of a quill. 



SPURIOUS. 



D. SEMISTRIATUM, Tui'toil. 



Dcntuilam semistrudum, Turt. Conch. Diction, p. 39, f. 68. — Brit. Mar. Conch, 

 p. 3. 



Notwithstanding that this species bears a marked resemblance 

 to D. inversum, the absence of the characteristic and peculiarly 



