DUNDET GASTEROPODA. 35 



This seems a somewhat variable shell as to elevation of the 

 spire. It is always less elevated than Muenster's figure (Goldf. 

 Petr. Germ. tab. 195, fig. 5) which is probably a different species. 



The Museum possesses the original specimen figured by 

 Sowerby. 



There are twelve specimens here. 



Locality — Dundry. Inf, OoU 



MONODONTA ACMON, D'Orbigny. 



1847 Trochus Acmon, D'Orb. Prodr. I. p. 265. 



1850 D'Orb. Pal. fr. Gast. pi. 314, 



figs. 1—4, p. 278. 



There are in the Museum four shells, which are much more 

 elevated than the last species, and which we place here, as they 

 correspond, as far as we can judge, with D'Orbigny's description. 



I fancy it probable that this may be a synonym of M. Laladei, 

 D'Arch. (Lycett and Morris, pi. 11, fig. 2). 



The Prench examples are cited from the Inf. Oolite of Bayeux. 



Our four specimens are from Dundry. 



Inf. Ool. 



STEAPAROLLUS DUI^DRIENSIS, n. sp. PI. 2, fig. 9. 

 Height 9 mm. Breadth 18 mm. 



Shell depressed, discoidal; excavate below, but the whorls 

 forming one plane above. Last whorl convex, thick ; its height 

 being equal to half the total breadth of the shell, ornamented on 

 the sides with spiral lines, which are finely tuberculate where 

 they are crossed by the curved transverse ones. Upper angle of 

 the whorl less than a right angle somewhat, its edge ornamented 

 with numerous sharp tubercles, decussated by spiral lines. The 

 upper surface of the whorl has four dotted spiral lines between 

 the rows of tubercles. The umbilical region is imperfect. 



There are two specimens in the Museum. 



Locality — Dundry. Inf. Ool. 



