GASTEROPODA. 79 
PLEvROTOMARIA OBESA, Des/. Plate X, fig. 11. 
PLEUROTOMARIA OBESA, Deslongchamps. 1848. Mém. Soc. Linn. de Normandie. 
vol. viii, p. 134, pl. 14, fig. 1. 
-—- - D’Orb. 1850. Prod. Paléont., p. 302. 
P. Testé trochiformi, apice subacuto, anfractibus rotundatis, in medio subdepressis, 
transverse striatis ; striis frequentibus obsoletis, equalibus, sinu angustissino, profundissimo, 
fascia sinks strictissimd, vie a striis distinctd, longitrorsum tamen densissime striatd, in medio 
anfractuum sitd, ultimo anfractu ad basim angulato-conveao ; basi subconvexd concentricé 
striata, striis rarioribus obsoletissimis, hine et indé evanescentibus, umbilico magno, pervio 
(parietibus subplanis), ad marginem sulcato, sulco sat parvo, spiraliter ascendente, suture 
interne vicino, sed ab ea distinctissimo; apertura subquadratd. (Deslongchamps.) 
Shell trochiform, apex subacute ; whorls somewhat convex, slightly depressed in their 
middle, and transversely striated ; the strie, which are equal, are frequently obsolete ; the 
sinus is narrow and deep, the band very narrow, so as scarcely to be distinguished from 
the striz ; but it is densely striated longitudinally, and situated in the middle of the whorls ; 
the last whorl is convexly angulated at the lower margin; the base is somewhat convex, 
concentrically striated, the strie being frequently scarcely distinguishable ; the umbilicus 
is large, pervious (the sides nearly flat), sulcated at its margin, and ascends the interior 
spirally, near to the internal sutures, but distinct from them; the aperture is subquadrate. 
Locality. We have only procured two specimens, which do not fully exhibit the 
minute features of this species, so carefully described by M. Deslongchamps. Both were 
obtained from the planking of Minchinhampton Common. Great Oolite, Ranville. 
(Desi.) 
PLEUROTOMARIA CLATHRATA, Goldf. Plate X, figs. 6, 6a. 
? PLEUROTOMARIA CLATHRATA, Goldfuss. 1843. Petref, p. 74, t. 186, fig. 8. 
_ _ D Orb, 1850. Prod. Paleont., p. 356. 
P. Testdé trochiformi subdepressd, apice acuto, anfractibus planis, (5,) cingillis lineisque 
crebris clathratis ; basi convexo-pland tenuissimée clathrata ; umbilico minimo aut nullo; 
anfractibus superne obsolete tuberculatis ; fascia sinis marginal. 
Shell trochiform, somewhat depressed ; apex acute; whorls (5) flattened, their sutures 
well marked ; covered with very fine, regular, equal lines, both longitudinal and transverse ; 
the base is flattened or slightly convex, with a very fine cancellated surface ; umbilicus 
