Stephen Fry, in his book The Ode Less Travelled, discusses meter in some detail, and provides this interesting angle on the ‘Pyramus and Thisbe’ segment of A Midsummer Night’s Dream:

Nabokov, in his Notes on Prosody, suggests that the hexameter [i.e a six-stress line] is a limit ‘beyond which the metrical line is no longer felt as a line and breaks in two’. Heptameters, seven-stress lines, are possible, and certainly do tend to ‘break in two’. They are known in the trade as ‘fourteeners’, referring to the usual syllable count. Here’s a line from Hardy’s ‘The Lacking Sense’.

Assist her where thy creaturely dependence can or may

As you can see, it is perfectly iambic (though one could suggest demoting the fourth foot to a pyrrhic):

Assist | her where | thy creat | urely | depend | ence can | or may

Actually, fourteeners were very popular in the sixteenth century, although Shakespeare disdained their use, a fact which has been adduced by some to damn the claims of Edward de Vere, seventeenth Earl of Oxford, as the real author of the Shakespearean canon, for Oxford loved them:

My life through lingering long is lodged, in lair of loathsome ways,
My death delayed to keep from life, the harm of hapless days.

This preposterously over-alliterated couplet hardly seems Shakespearean – in fact, Shakespeare mocked precisely such bombastic nonsense in ‘Pyramus and Thisbe’, the play-within-a-play performed by Bottom and the other unlettered ‘rude mechanicals’ in A Midsummer Night’s Dream, having great fun at the expense of Oxfordian fourteeners and their vulgar alliterations:

But stay: O spite! But Mark, poor knight, What dreadful dole is here?
Eyes, do you see? How can it be? O dainty duck, O dear.

You may notice that Hardy’s example is a ‘true’ heptameter, whereas Oxford’s lines (and Shakespeare’s parody of them) are in effect so broken by the caesuras after the fourth foot that they could be written thus:

My life through lingering long is lodged,
In lair of loathsome ways,
My death delayed to keep from life,
The harm of hapless days.

But stay: O spite! But Mark, poor knight,
What dreadful dole is here?
Eyes, do you see? How can it be?
O dainty duck, O dear.