You can remove the Bookmarks Menu button on the Bookmarks Toolbar with code in userChrome.css

Add code to userChrome.css below the @namespace line.

• http://kb.mozillazine.org/userChrome.css
• http://kb.mozillazine.org/Editing_configuration

You can use the ChromEdit Plus or Stylish extension to have easier access to the customization files.

• ChromEdit Plus: http://webdesigns.ms11.net/chromeditp.html

#personal-bookmarks #bookmarks-menu-button { display:none !important; }

See also:

• /questions/813898

Sorry, but I don't have a clue what that means. I don't use Chrome. I use Firefox on an I-Mac. Everything is the latest version.

You can open the Toolbar Customize mode and drag that icon into the Palette, to get if off the Bookmarks Toolbar.

https://support.mozilla.com/en-US/kb/How+to+customize+the+toolbar
http://kb.mozillazine.org/Toolbar_customization

I click View, Toolbars, customize, and the toolbar goes away, not allowing me to drag anything, because it's not there. I window pops up giving me options, but I can't see the toolbar. Also, what is a palette?

That Bookmarks Menu button on the Bookmarks Toolbar is part of the Bookmarks Toolbar Items and can't be dragged.
There is a second button (star with a drop marker) in the Customize window (palette) that can be dragged on another toolbar.

The file userChrome.css is a file that allows to customize the user interface and that file has nothing to do with (Google) Chrome, so do not get confused by the name.

See:

• http://kb.mozillazine.org/Editing_configuration

You can use the ChromEdit Plus or Stylish extension to have easier access to the customization files.

• ChromEdit Plus: http://webdesigns.ms11.net/chromeditp.html

Cor-el

 Installed ChromeEdit Plus, but it's way too advanced for my skills, and somehow messed up my I-Mac, at least in Firefox.  It has slowed to a crawl, and many normal setting changed.  Could you please tell me how to remove it?

Thanks

See:

• http://kb.mozillazine.org/Uninstalling_add-ons

Do you remember which changes you made and to which of the three files that can be modified via the extension?

You can find the files userChrome.css and userContent.css in the chrome folder in the Firefox Profile Folder.

• http://kb.mozillazine.org/Profile_folder_-_Firefox

Help > Troubleshooting Information > Profile Directory: Open Containing Folder

It shouldn't make any difference for responsiveness if you made the changes and added the above posted code.
The Windows version only shows that Bookmarks Menu button if the menu bar is hidden, but on Mac you also seem to see it when the menu bar is displayed (you can't hide the menu bar on Mac anyway).