THIRD SUPPLEMENT TO THE CRAG MOLLUSCA. 



GASTEROPODA. 



ROSTELLARIA? GRACiLENTA, S. Wood. 3rd Sup., Tab. I, fig. 1. 



Axis, 1 inch. 



Locality. Red Crag, Felixstowe. 



Many years ago I found a few specimens in the Red Crag at Sutton, to which I gave 

 the provisional name of Rostettaria plurimacosta in my original Catalogue in ' Mag. Nat. 

 Hist./ September, 1842, p. 543. Not finding any of the like form and character in 

 better preservation I, in the first supplement (1872) to my work on the ' Crag Mollusca ' 

 (p. 5, Tab. II, fig. 14), gave a figure with the best information I possessed respecting 

 the few specimens in my own cabinet, and referred them (doubtfully) to a well-known 

 Eocene species R. lucida, J. Sow. 



In my recent researches at Eelixstowe I have obtained three or four more specimens 

 of this shell, though in a more mutilated condition. With these I have found some other 

 mutilated specimens, the best of which I have here had figured. This resembles in its 

 ornamentation the Eocene species lucida, which is from the upper part of the London 

 Clay (' Min. Con.,' Tab. 91), but it differs in other respects, as it is much more slender, 

 more elongated, and possesses larger and fewer costulae. Unfortunately the mouth 

 or aperture is imperfect so that the genus cannot with certainty be determined. I, 

 however, propose for it provisionally the name above. It is undoubtedly an immature 

 specimen, with its outer lip sharp as it would naturally be in a young and growing 

 shell. 



In the Ipswich Museum there is a mass of material, nearly two feet across and about 

 three inches in thickness, found in the nodule bed at the base of the Red Crag at 

 Waldringfield, and on the upper surface are a large number of specimens of a vermiform 

 shell identical with what has been figured in ' Min. Conch./ Tab. 596, figs. 1 3, as 

 Vermetus Bognoriensis, and with them are several specimens, but in a mutilated 

 condition, of what may be referred to Rostettaria lucida, as also some specimens resem- 

 bling my present shell in a similar condition to my own above figured. There can 



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