CREPIDULA KORNICATA, L., OFF THE COAST OF ESSEX 37 



been laid down, but never before this that American ones were also 

 employed for this purpose. 



Having a meeting of the Essex Field Club next day at St. 

 Osyth, and along the sea-wall, I exhibited the shell, and subse- 

 quently made a note of it in The Essex Naturalist (Vol. v., p. 260, 

 Dec, 1891.) 



I thought no more about this occurrence until the 4th of 

 March, 1893, when I received a small parcel of marine forms from 

 the Crouch river, taken by John Bacon whilst engaged in the 

 oyster fishery on board a Burnham smack. Amongst the contents, 

 fish, nudibranchs, etc., I found a living example of the same 

 Crepidula, which he mentioned in his letter as a "Crow oyster on a 

 Stone." It maybe well to add that Burnham, close to which these 

 were taken, is about sixteen miles in a straight line from Stone 

 Point, and by sea round the coast of the Dengie Hundred and up 

 the river, over twenty miles. I wrote back at once to Bacon to ask 

 if this was the first shell of the kind he had seen, and requested 

 him to look out for more ; to which he replied : " I can remember 

 these for fifteen to twenty years ; although I have known them so 

 long they are very scarce. I have caught them in different parts of 

 the Crouch and Roach rivers. I do not know, nor do I think, that 

 any American oysters or spat has ever been laid down in either of 

 our rivers." 



Later on he told me that he had heard they were fairly common 

 in the Blackwater ; but neither my friend Mr. Fitch, F.L.S., who 

 knows the river well, nor myself, has ever caught it whilst dredg- 

 ing, though we have taken over fifty species of moUusca in that 

 river. 



On the 15th of April, Bacon sent me another live specimen, and 

 one to Mr. Fitch ; both of these were from oysters at the Ferry 

 layings (Cricksea). My specimen died during the night, but I took 

 it up the next day to the Natural History Museum to show Mr. 

 Edgar A. Smith ; and we there took out the animal and put it in 

 spirit. The shell of this is very concave, and rich in colour inside, 

 the septum pure enamel-white ; and we then compared it with 

 shells from North America in the Museum, which were practically 

 identical. 



When visiiing Maldon, later on, Mr. Fitch gave me the other 

 shell. It is larger, flatter, and the inside colour more mottled ; and 

 the oyster on which it was found is not a native, but a French one 



