http://www.925-1000.com/british_marks.htmlThis is a great site for World wide example of Silver Marks of all purities and plates.
For the example shown you will see about 4 stamps stringed together on in a line fashion. Each marking shows certain kind of information such as year made, city , and if duties are paid, etc.
ALL precious metals must be hallmarked like this according to the Assay offices of England- like where this item is made.
A rampant lion marking is a lion on its hind legs 'clawing' the air. I think its London's city marking which is most common of the British Markings.