You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <alltransclusions gatcontinue="Beanbox|49" />
  </query-continue>
  <query>
    <pages>
      <page pageid="33" ns="0" title="Blue Shackamaxon" />
      <page pageid="34" ns="0" title="Tobacco Worm" />
      <page pageid="35" ns="0" title="Alice Sunshine" />
      <page pageid="36" ns="0" title="Giant Red Tarka" />
      <page pageid="38" ns="0" title="Rose" />
      <page pageid="39" ns="0" title="Hill Family Greasy" />
      <page pageid="41" ns="0" title="Grandma Nellie&#039;s Yellow Mushroom" />
      <page pageid="43" ns="0" title="Tarahumara Burro and Caballito" />
      <page pageid="45" ns="0" title="Scuba" />
      <page pageid="46" ns="0" title="True Red Cranberry" />
    </pages>
  </query>
</api>