COLUMBELLA (COLUMBELLOPSIS) BORSONI. 309 



of the shell ; mouth short, oval ; outer lip grooved internally ; canal distinct, very 

 short. 



Dimensions. — L. 12 — 18 mm. B. 6 — 8 mm. 



Distribution. — Not known living. 



Fossil: Coralline Crag : Boyton. Waltonian : Walton-on-Naze, 

 Beaumont, Little Oakley. Newbournian : Bentley, Waldringfield, Sutton. 

 Butleyan : Butley, Shottisham. Isle of Man. 



Remarks. — This shell is very abundant at Oakley where I have obtained nearly 

 100 specimens of it; except that it has been recently found in the Manxland drift, 

 it has not been reported from any other formation than the English Crag. It is 

 easily distinguished from the last species by its slender form, its smaller size, its 

 more solid character, its more distinct sculpture and the shape of its mouth and 

 its canal. Nyst identified it with G. sulcata, but this view I am unable to accept. 1 



Sub-genus COLUMBELLOPSIS, Bucq., Dautz. et Dollf., 1882. 

 Columbella (Columbellopsis) Borsoni (Bellardi). Plate XXXIII, figs. 20, 21. 



1848. Columbella Borsoni, Bellardi, Mon. Colurnb., p. 14, pi. i, fig. 11. 



1872. Columbella Borsoni, A. and E. Bell, Proc. Geol. Assoc, vol. ii, pp. 209, 213. 



1874. Columbella Borsoni, S. V. Wood, Mon. Crag Moll., 1st Suppl, pt. ii, p. 174, add. pi., fig. 19. 



1890-1904. Columbella (Clinurella) Borsoni, Sacco, Boll. Soc. Geol. Ital., vol. ix, p. 224, no. 2897, 



1890 ; Moll. Terr. Terz. Piem., pt. vi, p. 45, pi. ii, fig. 52, 1890 ; C. (Atilia) Borsoni, pt. xxx, p. 94, 



1904. 

 1890. Columbella Borsoni, C. Eeid, Plioc. Dep. Brit., p. 242. 

 1901. Atilia Borsoni, Cossmann, Ess. Paleoconch. compar., vol. iv, p. 243. 



Specific Characters. — Shell small, subfusiform; whorls flattened, smooth, the 

 last about half the total length, excavated below ; spire polygyrate, acutely 

 conical ; mouth short, subquadrangular ; outer lip thickened outside, grooved 

 within ; columella excavated, contorted; canal short, distinct. 



Dimensions. — L. 10 mm. B. 4 mm. 



Distribution. — Not known living. 



Fossil : Waltonian Crag : Walton-on-Naze, Little Oakley. New- 

 bournian : Shottisham. Upper and Middle Miocene : Italy. 



Remarks. — Considerable difference of opinion has existed as to the correct 

 nomenclature of the present species, Prof. Sacco referring it in 1890 to a new sub- 

 genus Glinurella and in 1904 to Atilia, H. and A. Adams, as did M. Cossmann 

 in 1901; Chenu, however, figured as the type of the latter genus a different 

 form, Columbella suffusa, Sowerby. 2 I have adopted the sub-generic term Colum- 



1 There is a specimen from Waldringfield in the York Museum labelled Lachesis magna which I 

 believe is the same as the present species. 

 2 Man. Conch., vol. i, p. 201, fig. 1087. 



