Custom Post Type with Taxonomy

function themes_taxonomy() {  
    register_taxonomy(  
        'themes_categories',  //The name of the taxonomy. Name should be in slug form (must not contain capital letters or spaces). 
        'themes',        //post type name
        array(  
            'hierarchical' => true,  
            'label' => 'Themes store',  //Display name
            'query_var' => true,
            'rewrite' => array(
                'slug' => 'themes', // This controls the base slug that will display before each term
                'with_front' => false // Don't display the category base before 
            )
        )  
    );  
}  
add_action( 'init', 'themes_taxonomy');

//Registering Custom Post Type Themes
add_action( 'init', 'register_themepost', 20 );
function register_themepost() {
    $labels = array(
        'name' => _x( 'Themes', 'my_custom_post','custom' ),
        'singular_name' => _x( 'Theme', 'my_custom_post', 'custom' ),
        'add_new' => _x( 'Add New', 'my_custom_post', 'custom' ),
        'add_new_item' => _x( 'Add New ThemePost', 'my_custom_post', 'custom' ),
        'edit_item' => _x( 'Edit ThemePost', 'my_custom_post', 'custom' ),
        'new_item' => _x( 'New ThemePost', 'my_custom_post', 'custom' ),
        'view_item' => _x( 'View ThemePost', 'my_custom_post', 'custom' ),
        'search_items' => _x( 'Search ThemePosts', 'my_custom_post', 'custom' ),
        'not_found' => _x( 'No ThemePosts found', 'my_custom_post', 'custom' ),
        'not_found_in_trash' => _x( 'No ThemePosts found in Trash', 'my_custom_post', 'custom' ),
        'parent_item_colon' => _x( 'Parent ThemePost:', 'my_custom_post', 'custom' ),
        'menu_name' => _x( 'Themes Posts', 'my_custom_post', 'custom' ),
    );

    $args = array(
        'labels' => $labels,
        'hierarchical' => false,
        'description' => 'Custom Theme Posts',
        'supports' => array( 'title', 'editor', 'excerpt', 'author', 'thumbnail', 'comments', 'revisions', 'post-formats', 'custom-fields' ),
        'taxonomies' => array( 'post_tag','themes_categories'),
        'show_ui' => true,
        'show_in_menu' => true,
        'menu_position' => 5,
        'menu_icon' => get_stylesheet_directory_uri() . '/functions/panel/images/catchinternet-small.png',
        'show_in_nav_menus' => true,
        'publicly_queryable' => true,
        'exclude_from_search' => false,
        'query_var' => true,
        'can_export' => true,
        'rewrite' => array('slug' => 'themes/%themes_categories%','with_front' => FALSE),
        'public' => true,
        'has_archive' => 'themes',
        'capability_type' => 'post'
    );  
    register_post_type( 'themes', $args );//max 20 charachter cannot contain capital letters and spaces
}