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="Achomosphaera_alcicornu.jpg" />
  </query-continue>
  <query>
    <pages>
      <page pageid="15794" ns="6" title="File:. Chatangiella.jpg">
        <duplicatefiles>
          <df name="._Chatangiella_niiga.jpg" user="Maintenance script" timestamp="2016-12-30T17:39:51Z" />
        </duplicatefiles>
      </page>
      <page pageid="15793" ns="6" title="File:. Chatangiella niiga.jpg">
        <duplicatefiles>
          <df name="._Chatangiella.jpg" user="Maintenance script" timestamp="2016-12-30T17:39:51Z" />
        </duplicatefiles>
      </page>
      <page pageid="14564" ns="6" title="File:. Xanthidium from Ehrenberg1837b.jpg">
        <duplicatefiles>
          <df name="._Xanthidium_from_Ehrenberg1837b_orig.jpg" user="Maintenance script" timestamp="2016-12-03T17:22:28Z" />
        </duplicatefiles>
      </page>
      <page pageid="15641" ns="6" title="File:. Xanthidium from Ehrenberg1837b orig.jpg">
        <duplicatefiles>
          <df name="._Xanthidium_from_Ehrenberg1837b.jpg" user="Maintenance script" timestamp="2016-12-03T03:41:35Z" />
        </duplicatefiles>
      </page>
      <page pageid="15802" ns="6" title="File:. dinoflaj logo 32x32.gif">
        <duplicatefiles>
          <df name="._dinoflaj_logo_64x64.gif" user="Maintenance script" timestamp="2017-01-02T16:31:15Z" />
        </duplicatefiles>
      </page>
      <page pageid="15801" ns="6" title="File:. dinoflaj logo 64x64.gif">
        <duplicatefiles>
          <df name="._dinoflaj_logo_32x32.gif" user="Maintenance script" timestamp="2017-01-02T16:31:15Z" />
        </duplicatefiles>
      </page>
      <page pageid="15783" ns="6" title="File:Abratopdinium.jpg">
        <duplicatefiles>
          <df name="Abratopdinium_kerguelense.jpg" user="Maintenance script" timestamp="2016-12-22T00:13:59Z" />
        </duplicatefiles>
      </page>
      <page pageid="15789" ns="6" title="File:Abratopdinium kerguelense.jpg">
        <duplicatefiles>
          <df name="Abratopdinium.jpg" user="Maintenance script" timestamp="2016-12-22T00:13:57Z" />
        </duplicatefiles>
      </page>
      <page pageid="15522" ns="6" title="File:Achilleodinium.jpg">
        <duplicatefiles>
          <df name="Achilleodinium_biformoides.jpg" user="Maintenance script" timestamp="2016-12-03T03:42:25Z" />
        </duplicatefiles>
      </page>
      <page pageid="15132" ns="6" title="File:Achilleodinium biformoides.jpg">
        <duplicatefiles>
          <df name="Achilleodinium.jpg" user="Maintenance script" timestamp="2016-12-03T03:43:00Z" />
        </duplicatefiles>
      </page>
    </pages>
  </query>
</api>