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>
    <alllinks galcontinue="Balaena_mysticetus|1585" />
  </query-continue>
  <query>
    <pages>
      <page pageid="718" ns="0" title="Magnoliophyta" />
      <page pageid="918" ns="0" title="Species entries to make" />
      <page pageid="1357" ns="0" title="Internal:Species list" />
      <page pageid="1580" ns="0" title="Balaenoptera acutorostrata" />
      <page pageid="1581" ns="0" title="Balaenoptera borealis" />
      <page pageid="1582" ns="0" title="Balaenoptera edeni" />
      <page pageid="1583" ns="0" title="Balaenoptera musculus" />
      <page pageid="1584" ns="0" title="Balaenoptera physalus" />
      <page pageid="2215" ns="0" title="List of Indian medicinal plants" />
      <page pageid="2376" ns="0" title="Diversity of leaf shapes" />
    </pages>
  </query>
</api>