Index: wp-admin/includes/class-wp-comments-list-table.php
===================================================================
--- wp-admin/includes/class-wp-comments-list-table.php	(revision 18555)
+++ wp-admin/includes/class-wp-comments-list-table.php	(working copy)
@@ -311,7 +311,12 @@
 
 		$this->user_can = current_user_can( 'edit_comment', $comment->comment_ID );
 
-		echo "<tr id='comment-$comment->comment_ID' class='$the_comment_status'>";
+		$data_commenttype = 'comment';
+		if ( !empty( $comment->comment_type ) ) {
+			$data_commenttype = esc_html( $comment->comment_type );
+		}
+
+		echo "<tr id='comment-$comment->comment_ID' class='$the_comment_status' data-commenttype='$data_commenttype'>";
 		echo $this->single_row_columns( $comment );
 		echo "</tr>";
 	}