Using phpunit, what should I do to have the code coverage report include the tests run via selenium?

Question

The coverage information is created by xdebug but instead of the inclusion into the coverage report, it creates a file with the information for every test in the webroot of the application.

I use the following setup:

class SeleniumTestCase extends PHPUnit_Extensions_SeleniumTestCase  {

public function __construct($name,array $data = array(), array $browsers = array()) 
{       
        parent::__construct($name,$data,$browsers);
        $url  = 'http://trax_test.localhost/';
        $url .= 'phpunit_coverage.php';
        $url .= '?'.$this->codeCoverageCookieName.'='.$this->testId;
        $this->coverageScriptUrl = $url;
        if(isset($_SERVER["SHELL"])) {
        echo("Coverage Url: ".$this->coverageScriptUrl."\n");
        }
    }

my selenium test classes are extensions of this general class.

Thanks for any suggestions.