Dear Sir

Your fact is an interesting one, & I am very much obliged to you for communicating it to me.—¹ You speak a little doubtfully about the name of the shell, & it w^d be indispensable to have this ascertained with certainty. Do you know any good conchologist in Northampton who c^d. name it? If so, I sh^d. be much obliged if you w^d. inform me of the result. Also the length & breadth of the shell & how much of leg (which leg?) of the Dytiscus has been caught.— If you cannot get the shell named, I could take it to the British Museum, when I next go to London; but this probably will not occur for about 6 weeks, & you may object to lend the specimen for so long a time. I am inclined to think that the case c^d. be worth communicating to “Nature”.—²

Again thanking you I remain, Dear Sir | yours faithfully Ch. Darwin

P.S. | I suppose that the animal in the shell must have been alive when the Dytiscus was captured; otherwise the adductor muscle of the shell w^d. have relaxed & the shell dropped off?