GASTEROPODA. 35 



The present shell is from the collection of Mr. Canham, who tells me he procured it 

 from the lower portion of the Cor. Crag at Sutton, and I have figured it in consequence 

 of its unusual size. This shell was originally figured in Min. Conch under the name of 

 T. lavigatus, and figured under that name by Nyst from the Belgian beds. In my 

 catalogue (1842) I called it pseudo-ziziphinus ; from its resemblance to the living ziziphinus, 

 and in the first vol. of Crag Moll, gave it as identical with that shell. It appears to be 

 identical in ornament (though not in form, being less tapering), with a specimen from the 

 Sicilian beds in my cabinet. This is probably the same as the shell living in the 

 Mediterranean called conulus. I have many Crag specimens, smaller than the one figured, 

 in which the exterior with its ornamentation is in perfection j and this so agrees with that 

 in conulus, that if our Crag shell called ziziphinus be only one of the living varieties of 

 that species, I think conulus and ziziphinus should be united. 



ASSIMINIA GRAYANA ? Leach. 2nd Sup., Tab. Ill, fig. 18 a, b. 



ASSIMINIA GRAYANA, Leach. Fleming's Brit. Anim., p. 275. 



Ford. Sf Hard. Brit. Mollusca, vol. iii, p. 70, pi. Ixxi, figs. 3, 4. 

 Jeffreys. Brit. Conch., vol. v, p. 99. 



Locality. Fluvio-marine Crag, Bramerton. 



Two specimens have been sent to me by Mr. J. Reeve as from the " Scrobicularia 

 bed at Bramerton," 1 having been thought by him to be something different from 

 Hydrobia ventrosa. One of these two I have here had represented, and I have referred 

 it with some doubt as above, as it does not strictly accord with the living shell, which is 

 obscurely angulated at the base of the last volution, like the shell of Hydrobia viva, 

 whereas in our present specimens the base is rounded. It differs materially from any 

 specimen of ventrosa that I have seen, and has not the depressed or deep suture of 

 Bythinia Leachii. In form it seems intermediate between B. tentaculata and If. 

 ventrosa. 



The shells at Bramerton being not unfrequently so distorted as to be scarcely 

 recognisable for the species, or even genus, to which they belong, it is possible that the 

 specimens in question are cases of this kind, so that I make the present reference with 

 all reserve. 



1 This Scrobicularia bed at Bramerton appears to intervene between the few feet of specially Fluvio- 

 marine Crag (4 of sect, xvi of the Introduction to my first ' Supplement') which rests on the chalk and 

 the Chillesford bed (5' of that section), thus answering exactly to the Scrobicularia beds at Butley, (4'" of 

 sect, xvii of the same Introduction) to which the fourth column of the synoptical list refers. 



