I have two drop down menus (html forms). I would like a user to make a selection from each form, click a submit button and have both selected values passed to a php page for processing. This is my failed attempt:

Code:
<body>
<form id="select_co" name="select_co" method="post" action="action.php">
 <select name="selected_co">
  <option selected="selected">Please select a County/City</option>
  <option value="1">A County</option>
  <option value="2">B County</option>
 </select>
 
<select name="selected_sp">
  <option selected="selected">Please select a Species</option>
  <option value="33">caiman</option>
  <option value="55">gator</option>
 </select>
<input name="" type="submit" />
</form>
The receiving php file:
Code:
<body>

<?php 
$selected_co;
$selected_sp;


echo $_POST['selected_co'];
echo "<br />";
echo $_POST['select_sp'];

?>
</body>
The selected_co value is passed, however the selected_sp value isn't. What am I doing wrong?