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"?>
    <allimages gaicontinue="71_opinion.pdf" />
      <page pageid="19478" ns="6" title="File:1815 married hanna saukey.jpg" />
      <page pageid="19477" ns="6" title="File:1822 obit winchester.jpg" />
      <page pageid="19567" ns="6" title="File:1833 barrons wharf.jpg" />
      <page pageid="19550" ns="6" title="File:1833 city hotel.jpg" />
      <page pageid="19481" ns="6" title="File:1865 08 25 nytribune unjust judge.jpg" />
      <page pageid="19557" ns="6" title="File:1867 chase samuel w obit.jpg" />
      <page pageid="19448" ns="6" title="File:1877 cambridge google earth image.jpg" />
      <page pageid="19560" ns="6" title="File:1896 bromley laurel cemetery.jpg" />
      <page pageid="19559" ns="6" title="File:1896 laurel cemetery 01.jpg" />
      <page pageid="19462" ns="6" title="File:69 opinion.pdf" />