SPHYRADIUM EDENTULUM. 7 



THE NON-MARINE MOLLUSC A OE THE CRAG. 



A. TERRESTRIAL. 



GASTEROPODA. 



But fe\y non-marine Molkisca were known to S. V. Wood from the Crag, 

 otherwise tlian from the Icenian, or as it lias been generally called, the Norwich 

 or Fluvio-marine series of these deposits. Since the publication of his Monograph, 

 however, a number of land and freshwater shells have been found in the upper or 

 Butleyan zone of the Red Crag by the brothers Robert and Alfred Bell, Mr. A. S 

 Kennard, Mr. P. Gr. H. Boswell, and others, indicating probably the proximity of 

 land to that part of the Crag Sea at the period in question. 



As far back as 1871, indeed, Mr. Alfred Bell had announced the discovery of a 

 seam in the Crag pit at Butley, near the Oyster Inn, where such forms were fairly 

 common.^ This seam, like many other sections of equal interest, is now unfor- 

 tunately obscured by talus. Much information has been obtained as to other 

 localities at which the species given by Wood have been found, and as to their 

 distribution, both recent and fossil. The description of the non-marine Mollusca 

 of the Crag, moreover, is scattered about in various parts of his work, while the 

 nomenclature now current differs in many cases from that there given. For such 

 reasons, and for the convenience of students, it seems desirable to treat the subject 

 de novo, but as briefly as possible, bringing together in a systematic way all the 

 information now available. I shall not deal with the non-marine Mollusca found 

 only in the freshwater bed at West Runton, as I understand that Messrs. Kennard 

 and B. B. Woodward are proposing to describe them elsewhere. 



Genn^^ SPHYRADIUM, Hartmann, 1841. 



Sphyradium edentulutn (Draparnaud). 



1805. Vertigo edentula, Draparnaud, Moll. terr. fluv. France, p. 52, pi. iii, figs. 28, 29. 

 1853. Pupa edentula, Forbes and Hanley, Brit. Moll., vol. iv, p. 108, pi. cxxx, fig. 1. 

 1862. Vertigo edentula, Jeffreys, Brit. Conch., vol. i, p. 268, pi. xvi, fig. 6. 

 1879. Pupa edentxda, S. V. Wood, Mon. Crag Moll., 2Qd Suppl., p. 37, tab. iv, fig. 6. 

 1890. Pupa edentula, C. Reid, Plioc. Dep. Brit., p. 229. 



1897-1901. Sphyradium edentulum, Keuoard and B. B. Woodward, Essex Nat., vol. x (table), 1897; 

 Proc. Malac. Soc, vol. iii, p. 190, 1899 ; Proc. Geol. Assoc, vol. xvii, pp. 214 et seq., 1901. 



1 Geol. Mag., vol. viii (1871), p. 452. 



