36 SECOND SUPPLEMENT TO THE CRAG MOLLUSCA. 



Valvata cristata, Miiller. 2nd Sup., Tab. IV, fig. 8 a, h. 



Valvata ckistata. Mull. Hist. Verm., pt. ii,'p. 198. 



Locality. Eluvio-marine Crag, Bramerton. 



This shell is abundant in the Freshwater deposits of Stutton, Grays, and Clacton, 

 but I have only met with the one now figured from the Eluvio-marine Crag. 



Valvata piscinalis. 2nd Sup., Tab. IV, fig. 9. 



Locality. Eluvio-marine Crag, Bramerton. 



This is also very abundant in the same Freshwater deposits, but it is very rare in 

 the Eluvio-marine Crag; it so closely resembles Margarita helicina that it is very 

 difficult to distinguish the difference, and scarcely possible, except with perfect 

 specimens; and I am doubtful whether a specimen found by Mr. Harmer at March, 

 given by me at p. 121 of Vol. XXIII of the ' Quart. Journ. Geol. Soc.,' as Trochus 

 /lelicinns, may not be merely Valvata piscinalis , since, Ereshwater shells occasionally occur 

 in the March gravel. 



The figure previously given of V. piscinalis^ ' Crag Moll.,' Tab. XII, fig. 3, 

 represents the depressed form, and I have given the more elevated one, which, when 

 first discovered, was considered as a distinct species, and called antiqua. 



The reference of Margarita helicina to the Coralline Crag made in my Catalogue 

 of 1842 was an error. 



Limn.s;a auricularia, Linne. 2nd Sup., Tab. IV, fig. 3 a. 



Helix aubiculabia, Linn. Syst. Nat., edit. 12, p. 1249. 

 LlMN^SA — Jeffreys. Brit. Conch., vol. i, p. 108, pi. vii, fig. 4. 



LiMNiEUs AUEiccLABius, var. ACUTUS, Forb. ^ Hani. Vol. iv, p. 171, pi. cxxiii, 



fig. 2. 



Locality. Eluvio-marine Crag, Bramerton. 



A single specimen, as above represented, has been sent to me by Mr. Reeve, and it 

 is the first instance that I have met with of this species having been found in the Crag. 

 It is, however, present in most of our newer Pliocene Ereshwater beds, as may be 

 seen in my List, ' Crag Moll.,' vol. ii, p. 307. Dr. Jefiieys gives three varieties 

 to this species, our shell agreeing best with the one he first gave as distinct {Limnaus 

 acutus in ' Linn. Trans.,' xvi, p. 373), but which he afterwards reduced to a variety. 

 Our fig. 3 b was made from a recent specimen by mistake. 



