﻿BIVALVIA. 



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Glacial of Hopton Cliff. 1 The Leda liyperborea of Mr. A. Bell's list in 'Arm. and 

 Mag.,' Sept., 1870, from Butley, is, I think, the above oblongoides. 



Leda semistriata, 8. Wood. Crag Moll., vol. ii, p. 91, Tab. X, fig. 10. 



In his list in White's ' Directory/ Dr. Woodward gave, on the authority of a single 

 valve in the Middleton collection, this species from the Norwich Crag. I suspect that 

 this was a spurious specimen. I know this species from no newer bed than the Coralline 

 Crag. 



Leda lanceolata, /. Sow. Crag Moll., vol. ii, p. 88, Tab. X, fig. 16. 



Localities. Red Crag, Bawdsey. Fluvio-marine Crag, Bramerton. Chillesford bed, 

 Chillesford. Middle Glacial, Hopton. 



A considerable fragment of this shell, exhibiting the wavy line ornamentation of the 

 exterior, has occurred in the Middle Glacial sand of Hopton, and a similar fragment in 

 the Fluvio-marine Crag of Bramerton. 



Leda myalis ? Couthouy. Supplement, Tab. IX, fig. 2 a, b. 



Nucula myalis, Couth. Bost. Journ. Nat. Hist., vol. ii, p. 61, pi. 3, fig. 7, 1838. 



Locality. Fluvio-marine Crag, Postwick. Lower Glacial, Runton. 



The specimen figured is one in the British Museum, and agrees with the recent 

 myalis of Couthouy in all respects, but I question whether after all it is anything more 

 than an extreme form of the preceding species oblongoides. The specimen figured is, with 

 another valve in the British Museum, marked " Postwick/' and a third there is marked 

 " Runton " which can only be from the Lower Glacial sands, which are fossilliferous at 

 that place. 



Fig. 13a, b, of 'Crag Moll./ Tab. X, may retain the name of L. caudata, Donovan, 

 and fig. 12 a, b, of the same plate I will refer to minuta, Mont. This latter is from the 

 Red Crag, and the caudata is the Bridlington form. 



1 It is the shell referred to under the name limatula in the list in ' Quart. Journ. Geol. Soc./ vol. xxvi, 

 p. 94. 



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