40 DUK^DEY GASTEROPODA, 



Shell conical, whorls 8 — 9, convex, somewhat ogival in outline 

 from the sinus-band being in a concavity. The whole shell is 

 adorned with knotted longitudinal lines, crossed by oblique 

 transverse broad ridges and finer lines. The very prominent 

 ridge, at the base of the last whorl, has the spiral lines stronger 

 than on the rest of the shell, and is crossed by broad transverse 

 costse. There is apparently no umbilicus: Ease very slightly 

 convex, with concentric lines, which seem to cease about half-way 

 towards the umbilicus. 



The sinus-band is concave, and is crossed by curved lines with 

 one medium longitudinal line. 



This form is very near to P. mutahilis v ar ccelafa, Desl. (Mem. 

 Soc. Linn, de l^orm. YIII. pi. 10, fig. 17). 1 do not even adopt 

 the varietal name, for ours diff'ers in the whorls being more convex 

 in outline, and the description of the sinus-band is quite different. 

 Deslongchamps' species has been dismembered by D'Orbigny, and 

 rightly I think. 



"We have only one specimen in our Museum. 



Locality — Dundry. Inf. Ool. 



It is named in honour of our President, Mr. "W. Sanders, F.E.S. 



PLEUROTOMARIA AGATHA, D'Orbigny. 



1847 P. agatha, D'Orb. Prodrome I. p. 268. 



1850 D'Orb. Pal. fr. Terr. Jur. 2 Gast. pi. 



383, figs. 1—3, p. 474. 

 Syn? 1840 P. mutabilis var coelata, Desl. Mem. Soc. Linn. 



de Norm. YIII. pi. 10, figs. 17. 



Height 19 mm. Breadth 22 mm. Angle of spire, Qb^. 



There is doubt about this identification. I do not feel quite 

 sure that this and P. mutahilis as restricted by D'Orbigny are 

 distinct species. D'Orbigny has apparently merely copied on his 

 Plate (384) the drawing of Deslongchamps' var. corrugata . 



