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>
    <allimages gaicontinue="Acanthophoenix_crinita_flower_spathe_Levine.JPG" />
  </query-continue>
  <query>
    <pages>
      <page pageid="2393" ns="6" title="File:ACROCOMIA aculeata NN.JPG" />
      <page pageid="2447" ns="6" title="File:ARchonto alexandrae pair SD Zoo.JPG" />
      <page pageid="114" ns="6" title="File:ARchontophoenix purpurea Schwarz.jpg" />
      <page pageid="5373" ns="6" title="File:ARenga micrantha base GGP.jpg" />
      <page pageid="195" ns="6" title="File:Acanthophoenic rubra closer.jpg" />
      <page pageid="181" ns="6" title="File:Acanthophoenix 1 levine.JPG" />
      <page pageid="187" ns="6" title="File:Acanthophoenix crinita.JPG" />
      <page pageid="186" ns="6" title="File:Acanthophoenix crinita Velez.jpg" />
      <page pageid="182" ns="6" title="File:Acanthophoenix crinita crownshaft L.JPG" />
      <page pageid="184" ns="6" title="File:Acanthophoenix crinita flower.JPG" />
    </pages>
  </query>
</api>