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="Cycad_Links|45" />
  </query-continue>
  <query>
    <pages>
      <page pageid="4" ns="14" title="Category:Cycads" />
      <page pageid="36" ns="0" title="Macrozamia lucida" />
      <page pageid="37" ns="0" title="Macrozamia lucida Links" />
      <page pageid="38" ns="0" title="Macrozamia macdonnellii" />
      <page pageid="39" ns="0" title="Macrozamia macdonnellii Links" />
      <page pageid="40" ns="0" title="Macrozamia miquelii" />
      <page pageid="41" ns="0" title="Macrozamia miquelii Links" />
      <page pageid="42" ns="0" title="Macrozamia montana" />
      <page pageid="43" ns="0" title="Macrozamia montana Links" />
      <page pageid="44" ns="0" title="Macrozamia moorei" />
    </pages>
  </query>
</api>