mounted webdav filesystem disappears from view but says still mounted

[jerry57]

from a Mac OS X 10.10 machine I mounted a webdav filesystem. Coming in next day, "df -h" and "mount" both show the filesystem as mounted, but doing an "ls -a" on the parent does not even show the mountpoint.

attempting to change to the directory results in error, but tab completion thinks it is still there

poplar:~ jerry$ cd /Users/jerry/webdav_mount (this was typed by using tab completion in bash)
cd: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory

poplar:WebDav_Testing jerry$ df -h
Filesystem Size Used Avail Capacity iused ifree %iused Mounted on
/dev/disk1 465Gi 420Gi 44Gi 91% 110226303 11611295 90% /
devfs 186Ki 186Ki 0Bi 100% 642 0 100% /dev
map -hosts 0Bi 0Bi 0Bi 100% 0 0 100% /net
map auto_home 0Bi 0Bi 0Bi 100% 0 0 100% /home
https://vm64-243.iplantcollaborative.org/ 0Bi 0Bi 0Bi 100% 0 0 100% /Users/jerry/webdav_mount

poplar:WebDav_Testing jerry$ mount
/dev/disk1 on / (hfs, local, journaled)
devfs on /dev (devfs, local, nobrowse)
map -hosts on /net (autofs, nosuid, automounted, nobrowse)
map auto_home on /home (autofs, automounted, nobrowse)
https://vm64-243.iplantcollaborative.org/ on /Users/jerry/webdav_mount (webdav, nodev, noexec, nosuid, mounted by jerry)

poplar:webdav_mount jerry$ ls -al /Users/jerry/
ls: webdav_mount: No such file or directory
total 208
drwxr-x---+ 55 jerry staff 1870 Jan 6 09:41 .
drwxr-xr-x 6 root admin 204 Oct 22 2014 ..
-r-------- 1 jerry staff 7 Oct 22 2014 .CFUserTextEncoding
-rw-r--r--@ 1 jerry staff 10244 Apr 2 2015 .DS_Store
drwx------ 4 jerry staff 136 Jan 7 08:45 .Trash
-rw-r--r--@ 1 jerry staff 4356 Nov 13 13:55 .bash_aliases
-rw-------@ 1 jerry staff 18966 Jan 6 11:18 .bash_history
-rw-r--r--@ 1 jerry staff 1610 Jan 21 2015 .bash_profile
drwxr-xr-x 3 jerry staff 102 Sep 22 2014 .config
drwx------ 3 jerry staff 102 Sep 3 2014 .cups
drwxr-xr-x 13 jerry staff 442 Feb 3 2015 .dbvis
-rw-r--r-- 1 jerry staff 187 Nov 17 2014 .gitconfig
drwxr-xr-x 7 jerry staff 238 Jul 29 15:59 .idrop
drwx------ 288 jerry staff 9792 Jan 7 08:29 .irods
-rw-r--r-- 1 jerry staff 0 Jul 29 15:58 .jline-jython.history
-rw------- 1 jerry staff 403 Jan 6 09:36 .lesshst
drwxr-xr-x 3 jerry staff 102 Sep 23 12:33 .oracle_jre_usage
-rw-------@ 1 jerry staff 6640 May 26 2015 .pgpass
-rw------- 1 jerry staff 616 Nov 23 13:03 .psql_history
-rw------- 1 jerry staff 1024 Oct 6 15:23 .rnd
drwxr-xr-x 3 jerry staff 102 Sep 5 2014 .robotframework
-rw------- 1 jerry staff 1234 Dec 16 2014 .sqlite_history
drwxr-xr-x 6 jerry staff 204 Dec 17 10:34 .ssh
drwxr-xr-x 6 jerry staff 204 Dec 1 2014 .subversion
drwxr-xr-x 3 jerry staff 102 Oct 28 2014 .swex
-rw-r--r--@ 1 jerry staff 19 Oct 2 2014 .tm_properties
-rw------- 1 jerry staff 14735 Jan 6 09:41 .viminfo
drwxr-xr-x@ 3 jerry staff 102 Sep 15 15:25 .vnc
drwx------ 3 jerry staff 102 Jan 6 15:30 Applications
drwx------+ 27 jerry staff 918 Jan 7 08:45 Desktop
drwx------+ 21 jerry staff 714 Oct 31 2014 Documents
drwx------+ 14 jerry staff 476 Jan 6 15:21 Downloads
drwx------@ 53 jerry staff 1802 Jan 21 2015 Library
drwx------+ 3 jerry staff 102 Sep 21 2009 Movies
drwx------+ 3 jerry staff 102 Sep 21 2009 Music
drwx------+ 7 jerry staff 238 Jun 3 2014 Pictures
drwxr-xr-x+ 5 jerry staff 170 Sep 3 2014 Public
drwxrwxrwx 8 jerry staff 272 Nov 23 2011 Scripts
drwxr-xr-x 2 jerry staff 68 Jul 29 2014 Shared
drwxr-xr-x 2 jerry staff 68 Jul 23 2013 VB_Images
drwxr-xr-x 9 jerry staff 306 Sep 3 10:50 VirtualBox VMs
drwxr-xr-x@ 17 jerry staff 578 Mar 17 2015 apache-jmeter-2.12
drwxr-xr-x 12 jerry staff 408 Mar 17 2015 apache-jmeter-2.13
drwxr-xr-x 153 jerry staff 5202 Jan 7 06:19 bin
drwxr-xr-x 10 jerry staff 340 Jan 4 16:42 bonnie-64-read-only
-rw-r--r-- 1 jerry staff 440 Oct 29 2014 derby.log
drwxr-xr-x 23 jerry staff 782 Jul 30 07:53 iPlant_Info
drwxr-xr-x 14 jerry staff 476 Feb 25 2014 iRODS
lrwxr-xr-x 1 jerry staff 32 Mar 17 2015 jMeter -> /Users/jerry/apache-jmeter-2.13/
drwxr-xr-x 46 jerry staff 1564 Jan 6 14:10 junk
drwxr-xr-x 18 jerry staff 612 Oct 28 2014 jython2.7b3
drwxr-xr-x 142 jerry staff 4828 Jan 7 08:29 trunk
drwxr-xr-x 11 jerry staff 374 Sep 29 2009 trunk-NOAO
drwxr-xr-x 2 jerry staff 68 Sep 23 2013 trunk1