Adding the image...

In current Firefox releases (29 and later), that have have the Australis user interface, the orange Firefox menu button has been replaced by the three-bar Firefox Menu button at the far right end of the Navigation Toolbar and this button is always visible, whether you have the menu bar visible or hidden
A consequence of this location is that you no longer can hide the Navigation Toolbar

• There is a star like button next to the search bar on the Navigation Toolbar to bookmark the current web page and a "Show your bookmarks" button next to it to open the Bookmarks in a drop down menu.
  You can find "Show All Bookmarks" to open the Bookmarks Manager (Library) at the bottom of this drop-down list
• It is still possible to have the menu bar visible via the right-click context menu on the toolbars to have menus like the Bookmarks menu
• If you bookmark a page then "Bookmark This Page" in the Bookmarks menu changes to "Edit This Bookmark"

See also:

• https://support.mozilla.org/kb/how-to-make-new-firefox-look-like-old-firefox

• https://support.mozilla.org/kb/common-questions-after-updating-to-new-firefox
• https://support.mozilla.org/kb/learn-more-about-the-design-of-new-firefox

Thank you for your reply cor-el, I can see now, that Classic Theme Restorer can fix what Mozilla has fucked up.

Are there any release notes that explain why this feature was removed?

i thing you have removed the bookmark tool from the menu bar you can see your bookmarks as top right side of your Mozilla Firefox there are three lines click on it there you can find bookmarks