List Custom Post Type Titles in add_meta_box() HTML Output

My theme contains two custom post types, Biographies and Places. In the Places post type I have a meta box that contains an HTML select element. In this select element I want to have a list of all the Biographies post type titles.

I thought I would be able to do a WP_Query in the add_meta_box() $callback argument function to populate the list, but this does not seem to work. How would I go about doing this?

Thanks.