Google Feed API - returning media:thumbnail

I'm currently using the Google Feed API and attempting to retrieve a thumbnail from an RSS feed ("media:thumbnail")

The media:thumbnail line in the RSS feed looks like this:

<media:thumbnail url="http://ift.tt/1A2oCNm" width="150" height="150"/>

Note: The thumbnail is not part of a media:group

The script looks like this:

google.load("feeds", "1");

function initialize() {
  var feed = new google.feeds.Feed("http://ift.tt/1zlDqj9");
  feed.setNumEntries(20);               
  feed.load(function(result) {
    if (!result.error) {
      var container = document.getElementById("feed");
      for (var i = 0; i < result.feed.entries.length; i++) {
        var entry = result.feed.entries[i];
        var div = document.createElement("div");
        div.appendChild(document.createTextNode(entry.title));
        div.appendChild(document.createTextNode(entry.link));
        container.appendChild(div);
      }
    }
  });
}
google.setOnLoadCallback(initialize);

</script>

The TITLE and the LINK are returning just fine. But I don't see anything in the Feed API docs about returning media:thumbnail -- or specifically it's URL.

Anyone know how I might return the thumbnail URL using the feed API?