AH, leave the hills of Arcady,
Thy satyrs and their wanton play,
This modern world hath need of thee.
No nymph or Faun indeed have we,
For Faun and nymph are old and grey,
Ah, leave the hills of Arcady!
This is the land where liberty
Lit grave-browed Milton on his way,
This modern world hath need of thee!
A land of ancient chivalry
Where gentle Sidney saw the day,
Ah, leave the hills of Arcady!
This fierce sea-lion of the sea,
This England lacks some stronger lay,
This modern world hath need of thee!
Then blow some trumpet loud and free,
In the Middle Age, Lions were kept in the Tower of London. These were Barbary lions. As a symbol, “the Lion” was affixed as a nickname to those with a reputation with bravery. The most famous example is Richard I, AKA Richard the Lionheart. Lions have been a symbol in England for a long time. Wilde wrote this poem during the height of the English empire,  when England was the unrivaled power over the oceans. Without a challenge to their sea power, they were like a lion with control over the sea. This is why it is perhaps necessary to write not just sea-lion" but “sea-lion of the sea”. 

Pan: A Double Villanelle