GASTEROPODA. 71 



Locality. This little species is very rare. It occurs in the planking of Minchinhampton 

 Common. 



The specimen figured in the ' Min. Con.' is from the Oolite of Ancliff, Wiltshire ; 

 M. Buvignier describes his species as occurring in the Coral Rag of St. Mihiel, France. 



DELPHINULA BCCKMANNI. Plate V, fig. 8. 



D. Testa turbinatd, spird elatd, anfractibus (3 4) costatis ; ultimo anfractu ventricoso, 

 subquadrato, in media costato ; costis lonyitudinalibus, numerosis, rectis, et rotundatis, superne 

 acutis, striis transversis impressis ; umbilico contracto, striis tenuissimis cincto. 



Shell turbinated, spire elevated, whorls (3 4) costated, the last whorl ventricose, 

 subquadrate, costated in its middle portion ; the costa? are longitudinal, numerous, perpen- 

 dicular, acute at their upper extremities, and impressed with transverse striae ; the umbilicus 

 is contracted, and encircled with very fine stria3. 



The costee are scarcely visible upon the upper surface of the last whorl, and nearly 

 disappear towards its base ; the aperture is suborbicular, the lips being less incrassated than 

 is sometimes seen in this genus. Individual specimens vary very much in the elevation of 

 the spire, and in the degree of squareness or angularity which the last whorl acquires ; in 

 some the umbilicus is scarcely visible, which usually happens in the more elevated shells. 



Locality. This shell occurs in the beds of coarse planking on Minchinhampton 

 Common ; but well-preserved examples are rare. 



DELPHINULA ALTA. Plate IX, fig. 31. 



* 



D. Testa turbinatd; spird elatd, obtusd; anfractibus angulatis (interne rotundatis) ; 

 anfractu ultimo tuberculis acutis, crebris sed distinctis ornato ; basi quadricinctd, costulis 

 tuberculatis ; umbilico magno prof undo ; aperturd subquadratd. 



Shell turbinated j spire elevated, obtuse ; whorls angular (the moulds of the interior 

 being convex) ; the last whorl has, surrounding its upper part, a circle of elevated, acute, 

 distinct, and closely-arranged tubercles ; the base is encircled with four elevated ribs, 

 which are closely tuberculated ; the upper or flatter part of the last whorl has several fine 

 encircling lines (often indistinct) ; the umbilicus is large and deep, the aperture subquadrate 

 and rather small. 



Locality. Minchinhampton. This pretty shell occurs in the planking, and is not 

 uncommon ; but the coarseness of the deposit is unfavorable to the preservation of its 

 more delicate features. Our best specimens may therefore be regarded as some of the 

 choicer productions of the formation. 



