lot) 
specimens from Mr. D. Turner and Mr. Hooker, found 
in Norfolk. Mrs. Cobbold lias sent me a fragment of a 
larger still from Holywell, but it seems to be a thicker shell, 
and promises, from so much as I possess, to be another 
species. So good a specimen as this may therefore prove 
rather rare: it is from the Essex cliff at Harwich. The 
shell is probably Carbonate of Lime, little changed except 
by being stained by Iron ochre. 
