GASTEROPODA. 91 



species possesses a general resemblance to P. Aubentonensis, but the ribs are much more 

 elevated, closely arranged, and rugose. The figure given by M. Deslongchamps is more 

 elevated, but possesses no other essential distinctive character. Length 9 lines, breadth 

 7 lines, height 3 lines. 



Locality. Rare, in the planking of Minchinhampton Common ; also found in the 

 Inferior Oolite of Port-en-Bessin {Deslongchamps). 



Patella striatula. Plate XII, figs. 5, oa, b. 



P. Testa parvd, conicd, obtusd ; ambitu ovali ; costis radiantibus, tenuioribus, crebris, 

 Jlexuosis et nodulosis ; lineis incrementi irregularibus. 



Shell small, conical ; apex obtuse ; base oval ; with ribs radiating, fine, closely arranged, 

 waved, and nodulated ; lines of growth irregular. 



This species is more elevated than P. Aubentonensis, and the apex more obtuse ; the 

 costae are likewise finer and more closely arranged. 



Locality. In the soft shelly Oolite beneath the planking at Minchinhampton, where 

 it is rare. 



Patella Roemeri. Plate XII, figs. 6, 6 a, b. 



P. Testa ellipticd, depressd ; apice subcentrali ; costis (30) radiantibus elatis ; lineis 

 interstitialibus numerosis ; striis transversis impressis ; lineis incrementi irregularibus 

 paucis. 



Shell depressed, elliptical ; apex subcentral, with 30 radiating and elevated ribs ; inter- 

 stitial lines numerous, the whole being crossed and impressed by striae ; lines of growth 

 irregular and few. 



This elegant little species is sometimes nearly discoidal, the central portion being most 

 frequently denuded of costae ; the form is more nearly circular than P. Aubentonensis, and 

 more depressed ; the costce are more elevated and less rounded, the interstitial spaces 

 being much deeper. The longer diameter rarely exceeds 9 lines, the elevation being 

 about 2. 



Locality. It is moderately rare, but not confined to any one shelly bed, in the vicinity 

 of Minchinhampton. 



Patella aubentonensis, Arc/iiac. Plate XII, figs. 7, la, b, c, d. 



Patella Aubentonensis, Archiac. 1843. Mem. Soc. G6ol. de France, vol. v, p. 377, 



t. 28, fig. 8. 

 Helcion — D'Orb. 1850. Prod. Paleont., p. 304. 



