GASTEROPODA. 

 C 



, * ' _ 



7 JL^ * ~* ^ - -*- 



, MOW tMcnW JMM rtJKCCO. 



Shell ovately oblong; spire rather elevated; the last whori large and 

 aperture sometimes as long as the last whorl, narrow in its posterior, wider in 

 put ; lips continooBB and Terr thin, the inner lip not reflected upon the i 



The genus Cfriculvg was established by Cape. Brown, pon the recent 

 and was afterwards used to comprise certain species of recent a*d basil shells, previously 

 referred by authors to Battm* Ittatm, far. 1 Although the general form of the shells thas 

 classed together is somewhat "I*"' this character cannot always be caasidaed as 

 definite, inasmuch as the animal inhabitant of the fossil species may hare BMkanaftf cBfland 

 from the recent type. Ale. d'Orbigny, in recognising the generic duferences of some allied 

 forms, described as Tbnetetla, subsequently proposed in the ' Prodrome de Paleontologies 

 the name Jctmtmimt for their reception. The genus OrtAottomm, instituted by Deshayes, 

 includes an alh'ed series of shells, and connecting them with Jttftm aid Q*aVifc, if we 

 may judge from the figures given in the ' Traite Elementaire de Conchyliologie,' but of 

 which no description has yet been published. Upon the ground, therefore, of the doubtful 

 generic identity of the recent Btttta obtosa with our fossil sheik, we have preferred to adopt 

 the name proposed by D'Orbigny. 



ACTJ:OM> A OLIVJ;FOR*IS, Dvnker. sp. Plate \Tfl, fig. 14. 



BCULA ouTjiTOuns, foe* and Dwtttr. 1 >. : ' . N .-rdd. Oolitlu t. T, fig. 3. 

 ACTIOSD.A D'Ord. IS50. Prod. Paleont^ p. 353. 



Shell ovatelv cyundrical, smooth ; spire rather small, or but Kttte produced ; whoris 

 rather convex ; the upper part of the aperture narrow. 



Locality. Three examples only, varying much in size, are in our collection. They 

 occurred in the soft shelly stone (termed ovenstone) which overBes the weatherstooes at 

 Mmchinhauipton Common. It is a thinly-laminated deposit, which is sometimes nearly 

 made up of the valves of Ottrea acwmnata ; when these are absent, their place is occupied 

 by a multitude of small bivalves ; or, when these again become scarce, other and more 

 interesting forms occur, anioii^ which may be ranked the present species. 



1 With regard to the comparative ^eavrto dii&reucw of the fauhr ttKJm> the reader nftmd h aa 

 intewting p^per by Mr. Clark, published in the Annals of Natural History,' for August 185*. from which 

 it appears, by a careful study of the structure of th anuatls. that the generic subdtYiMM lalihlished by 

 some authors in this group are not well characterised. 



