Concerning SNAP related systemd services

I found a bunch of cryptic junk in my /etc/systemd/system directory. What are these snap related '.mount' service items? Can they be safely deleted?

 snap-firefox-3779.mount'snap-gnome\x2d3\x2d26\x2d1604-104.mount''snap-gnome\x2d3\x2d26\x2d1604-111.mount''snap-gnome\x2d3\x2d28\x2d1804-194.mount''snap-gnome\x2d3\x2d28\x2d1804-198.mount''snap-gnome\x2d3\x2d34\x2d1804-90.mount''snap-gnome\x2d3\x2d34\x2d1804-93.mount''snap-gnome\x2d3\x2d38\x2d2004-140.mount''snap-gnome\x2d3\x2d38\x2d2004-143.mount''snap-gnome\x2d42\x2d2204-132.mount''snap-gnome\x2d42\x2d2204-141.mount''snap-gnome\x2dsystem\x2dmonitor-184.mount''snap-gnome\x2dsystem\x2dmonitor-186.mount''snap-gtk\x2dcommon\x2dthemes-1534.mount''snap-gtk\x2dcommon\x2dthemes-1535.mount''snap-kde\x2dframeworks\x2d5\x2d102\x2dqt\x2d5\x2d15\x2d8\x2dcore22-5.mount''snap-kde\x2dframeworks\x2d5\x2d91\x2dqt\x2d5\x2d15\x2d3\x2dcore20-1.mount''snap-kde\x2dframeworks\x2d5\x2d96\x2dqt\x2d5\x2d15\x2d5\x2dcore20-7.mount''snap-kde\x2dframeworks\x2d5\x2dcore18-32.mount''snap-kde\x2dframeworks\x2d5\x2dcore18-35.mount''snap-kde\x2dframeworks\x2d5\x2dqt\x2d5\x2d15\x2d3\x2dcore20-8.mount'

Here is the contents of one of the snap-gnome ones...

[Unit]Description=Mount unit for gnome-3-28-1804, revision 194After=snapd.mounts-pre.targetBefore=snapd.mounts.targetBefore=local-fs.target[Mount]What=/var/lib/snapd/snaps/gnome-3-28-1804_194.snapWhere=/snap/gnome-3-28-1804/194Type=squashfsOptions=nodev,ro,x-gdu.hide,x-gvfs-hideLazyUnmount=yes[Install]WantedBy=snapd.mounts.targetWantedBy=multi-user.target

It seems that gnome is leaving a bunch of old version garbage around maybe? Thanks for any suggestions. Imho 'snap' is bringing down Ubuntu.