62 DinfDET GASTEROPODA. 



Our specimens correspond exactly with Sowerby's description ; 

 his figure, though sketchy, is faithful as to form. The surface of 

 this shell is covered with decussating lines ; the transverse ones 

 are inclined in opposite directions on either side of the sinus- 

 band; this is almost median, rather above the middle than below 

 it, and contains longitudinal crossed by curved lines. The 

 outline of the whorls is subangularly convex. The ornamentation 

 is more marked below the sinus-band than above it. 



It is distinguished from Deslongchamps' var physospira by the 

 absence of tubercles on the young whorls, less scalate outline, 

 &c. D'Orbigny seems quite right in making separate species of 

 what the former author considered erroneously to be Sowerby's 

 shell in question. 



The nearest to it in form is P. transilis, "D'Orb., but that has 

 no umbilicus. 



Dr. Brauns may perhaps be right (Mittel-Jura., p. 190) in 

 considering P. Niortensis, D'Orb., as a synonym of this species, 

 but the position of the sinus-band seems to be different. 



There are three specimens in the Museum. 



Locality — Dundry. Inf. Ool. 



PLEIJROTOMAEIA PROTEUS, Deslongchamps. 



1848 P. Proteus, Deslong., Minn. Soc. Linn, de Norm. 

 Yin., pi. 1, fig 1, and pi. 2, fig. 1. 



"We have an internal cast of a large shell which may probably 

 be referred here ; the size and shape are the only characters left to 

 judge by, as we have no specimen with the shell on. Its height 

 is six inches. 



It has been cited before by Dr. Wright and Mr. Etheridge. 

 One specimen only. 



Locality — near Bath. Inf. Ool. 



PLEITROTOMARIA YEOYILEI^SIS, n. sp. PI. 3, fig. 4. 

 Height, 14 mm. Greatest breadth, 21 mm. 



