rendering a collection of partial inserted in their layout

hi !

i've to render a collection of partial, each element need to be inserted
in a layout which render the html presentation.

<div class="my_layout">
  <div>collection_element_1</div>
</div>
<div class="my_layout">
  <div>collection_element_2</div>
</div>
...

render :partial, collection => @collection, :layout =>
'layouts/my_layout'
=> render the hole collection in a global layout

How would you do ?