[Plugin: Tag Gallery] constants TAGGALLERY and TAGGALLERY_URL generate notices

tag-gallery.php contains the statements:

define( TAGGALLERY, WP_PLUGIN_DIR . '/tag-gallery' );
define( TAGGALLERY_URL, WP_PLUGIN_URL . '/tag-gallery');

these produse the following notices:
Notice: Use of undefined constant TAGGALLERY – assumed ‘TAGGALLERY’
Notice: Use of undefined constant TAGGALLERY_URL – assumed ‘TAGGALLERY_URL’

changing the definitions to
define( 'TAGGALLERY', WP_PLUGIN_DIR . '/tag-gallery' );
define( 'TAGGALLERY_URL', WP_PLUGIN_URL . '/tag-gallery');

fixes the issues