GASTEROPODA. 169 



ORD. TECTIBRANCHIATA. 

 ACTION,* Montf. 1810. 



VOLUTA (spec.) Linn. 

 SOLIDULA. Fischer. 

 TORNATELLA. Lam. 1816. 



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

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

 above, rounded below ; outer lip plain, generally sharp ; columella spiral, with tooth- 

 like projection ; operculum corneous. 



1. ACTION NOJS. /. Sow. Tab. XIX, fig. 6, ab. 



ACTION NOJE. J. Sow. Min. Conch, t. 374, 1822. 



S. Wood. Catalogue 1842. 

 TORNATELLA No,E. Nyst. Coq. foss. de Belg. p. 424, pi. 37, fig. 22, 1844. 



A. Testa ovato-elonffatd vel subcylindraced ; spird conoided ; anfractibus septem vel octo 

 convexiusculis, transversim striatis; suturis depressis, subcanaliculatis ; columella uniplicatd, 

 labro acuto, intus sulcato. 



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

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

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



Axis, 1 inch ; diameter, ^. 



Locality. 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 three fourths of the length of axis. 



* Etym. Actceon, a proper name. 



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