GASTEROPODA. 25 



numerous, distant, and elevated a single one more elevated, being placed at the base of 

 each whorl. The longitudinal ribs are occasionally unequal, one unusually large sometimes 

 appearing, but not extending beyond the whorl, forming a varix after the manner of 

 Triton ; the columella is twisted, turned outwards at the base, and forms, with the outer 

 lip, a short oblique channel, which is not perceptible upon the back of the shell ; the outer 

 lip is thin and dentated externally by the elevated transverse lines. 



Locality. This species is moderately rare ; it occurs in the coarse bed of planking 

 at Minchinhampton Common, and is seldom well preserved. 



BRACHYTREMA TURBINIFORMIS. Plate IX, fig. 35, 35a. 



B. Testa turbinatd, vcntricosd, spird elevatd; anfractibus 4 anffustatis, convexis, nodulato- 

 carinatis; ultimo anfractu ventricoso, costulis longitudinalibus ; striis transversis numerosis, 

 impressis; aperturd subrotundd, canali subnullo, columella recta. 



Shell turbinated, ventricose ; spire elevated ; whorls 4, narrow, convex, their sutures 

 deeply impressed, having a nodulated carina; the last whorl is large and ventricose, having 

 small longitudinal ribs crossed by numerous transverse striae; the aperture is nearly round, 

 the canal reduced to a mere notch ; the columella straight. 



This species is chiefly distinguished from its congeners by a greater dilatation of the last 

 whorl, which is much expanded transversely. Unfortunately the beds of planking, which 

 contain this and various other small univalves with ornamented surfaces, is of so coarse a 

 structure, and adheres to the shells with such tenacity, that it is not often that their features 

 can be distinguished. Length 6 lines. 



Locality. Minchinhampton Common. 



Family BUCCINID.E. 



PURPUROIDEA, Lycett. 1848. 



MUREX, sp., Sow. 1827. 

 PURPURA, sp., Buvignier. 1843. 

 PCRPURINA, sp., D'Orb. 1850. 



P. Testa turbinatd, spird elevatd, aperturd non longiori, apice subacuto ; anfractibus 

 convexis, in media tuberculatis, anfractu ultimo ventricoso ; basi tmncatd, aperturd mb- 

 quadratd, superne acutd, inferne truncatd, latd ; canali lato, recurvato ; columella arcuatd, 

 rotundatd, Icevi, basi acuminatd, incurcatd; labio effuso, in medio subdepresso, labro tenui 

 et sinuato, umbilico obteclo. 



Shell turbinated ; spire elevated, not longer than the aperture, with a somewhat acute 

 apex ; whorls convex, nodulated in their middle part, the last whorl ventricose, the base 



