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SUPPLEMENT TO THE CRAG MOLLUSCA. 



Succinea putris, Limncea palustris, and what is probably Limnaa Holbollii from the same 

 locality. This latter (of which I have myself found several specimens) seems to differ 

 specifically from palustris in having a much deeper suture and more convex volutions. 

 B. lubricus is common in the Post-glacial Freshwater deposits of this country ; but I had 

 not before known it from any deposits so old as the Red Crag. The other species have 

 been previously figured as from the Fluvio-marine Crag, and are only mentioned here as 

 occurring in the Red Crag. I have, at p. 4 of this Supplement, given what appears to 

 me to be the true explanation of the occurrence of land and freshwater shells at this 

 locality of the Red Crag. 



Clausilia pliocena, S. Wood. Addendum Plate, fig. 22. 



I have very recently obtained another land shell from the Cor. Crag of Sutton. This 

 undoubtedly belongs to the above-named genus ; but its specific identity is rendered un- 

 certain by the fragmentary condition of the specimen. 



Some of the animals of this genus in the living state are of arboreal habits, and my 

 present specimen was probably, like Helix Suttonensis, carried into the Crag sea upon 

 some dissevered piece of timber, and there deposited among the marine shells, or it may 

 have been carried to sea on the feet or in the feathers of a bird. 



Helix Suttonensis, from the same locality, approaches nearer to a living Madeira species 

 than to any other that I have seen. I had hoped therefore to have been able to identify 

 the present fragment with some species of Clausilia from that island, but I have not 

 been successful in so doing ; and am compelled therefore to give it provisionally a new 

 name, for it does not agree with any British species known to me. 



Avicula PHALiENOiDES, S. Wood. Supplement, p. 109, Tab. VIII, fig. 12 a, b, and 



Addendum Plate, fig. 23. 



I have figured the hinge and umbonal portion of some shells of this genus from the 

 Cor. Crag near Orford. None of the specimens of A. tarentina with which I have been 

 able to compare the Crag fragments at all approach in the magnitude and thickness of 

 their hinges these Crag Avicula, which are about intermediate in this respect between the 

 living British and Mediterranean shell Tarentina, and the gigantic form from the Bord- 

 eaux beds called Phalanacea, Bast. There is such a close resemblance between the 

 largest of these Cor. Crag hinges and those of the Bordeaux fossil that I have 

 assigned to the Crag shell the specific name of Phalanoides. The fragments to which I 

 referred in the ' Crag Mollusca,' vol. ii, p. 51, as probably belonging to A. tarentina, 

 belong, no doubt, to the same species as the fragments here figured. 



