GASTEROPODA. 169 



Obd. tectibbanchiata. 



Action,* Montf. 1810. 



VoLUTA (spec.) Linn. 

 SoLTDULA. Fischer. 

 TOKNATELIA. Lam. 1816. 



Gen. Char. Shell ovate, convolute, subcylindrical, with a more or less elevated 

 spire ; striated or siilcated in a transverse or spiral direction ; aperture linear, narrow 

 above, rounded below ; outer hp plain, generally sharp ; columella spu-al, with tooth- 

 like projection ; operculum corneous. 



1. AcTJEON No^. /. Sow. Tab. XIX, fig. 6, a — b. 



ACT.EON No^. J. Sow. Min. Conch, t. 374, 1822. 



— S. Wood. Catalogue 1842. 



TOENATELLA No.E. Ni/sf. Coq. foss. de Belg. p. 424, pi. 37, fig. 22, 1844. 



A. Testa ovato-elongatd vel siilcylindraced ; spird conoided ; anfractibus septem velocto 

 convexiusculis, transversim stnatis; sidiiris depressis, subcanaliculatis ; columella unipUcatd, 

 labro acuta, intics sulcata. 



Shell elongato-ovate, or subcylindrical, with a conical spire ; whorls slightly convex, 

 regularly striated, or rather sulcated, transversely ; suture deep, subcanaliculated ; 

 aperture linear ; outer lip sharp, with the striae visible within. 



Axis, 1 inch ; diameter, ^. 



Lacality. Red Crag, Walton Naze and Brightwell. 



This species is not very rare at the above locality, though, from its extreme 

 fragility, it is difficult to obtain in perfect condition. The shell appears to have 

 undergone a slight diminution in magnitude, and to have shrunk from the inner lip, 

 perhaps from the loss of a more than ordinary quantity of animal matter. It is con- 

 sidered here as differing from A. tornatilis in having the spire rather shorter, and a 

 deeper and more distinct canal at the suture, which, however, might be produced by 

 the shrinking of the shell ; but the upper part of the volution is more rounded, and the 

 striae are regularly distributed over the surface, sometimes single, sometimes in pairs. 

 In the recent British shell they are larger and coarser at the base, and the fold upon 

 the columella is smaller. The deep sulci of the exterior are visible within at all ages 

 from the thinness of the shell. Aperture tliree fourths of the length of axis. 



* Etym. ActoEon, a proper name. 



22 



