I have counted six different lions from the period 1796-1818 solely on teaspoons, and I have put them in an order; I'd appreciate any disagreements. It would also be very helpful if I knew the dates when the duty marks were cusped.
The first lion in my timeline is what Trev called in a previous post on this subject the "letterbox" lion passant: a fitting name I think. The lion is on this spoon made by William Pearce (I think) whose "latest mention", according to Exeter and West Country Silver, was 1796. I have used this book for all my dates.

1. The "letterbox" lion passant c.1796: very distinctive cartouche and looks like his right paw is coming out of his head.

2. Lion in a square cartouche with a wavy bottom line: note the tip of the tail points upwards now and the right leg looks like it's coming out of the left one. I have attributed this to John Lake and not John Legg. John Lake worked only in 1800 I believe. Also, cusped duty mark which may have begun in 1797 and continued for a few years.

3. Crowned(?) lion in a cartouche with clipped corners: note the tail tip points backwards and the right leg is coming out of the lion's head. I have seen this lion used on an item by Parsons and Crees who worked 1797-1800. Cusped duty mark again.

4. Lion in an oval cartouche: I've seen this on an item by Parsons and Joseph Goss who, I believe started to work together in 1805. Cusping has gone. I think this mark was used throughout most of the first decade of the 19th century, but not before and not after.

5. 1810 and the date letter seems to have been started. The lion moves back into a rectangular cartouche and he again looks like he's wearing a crown.


1813 same

1815 same

6. 1818 and the crown seems to have gone.

I am by no means confident about all these assertions, but I am pretty sure that there is quite a strong pattern. Any comments will be extremely welcome.
Miles