When I try to install libtiff on my 64-bit Ubuntu, I get the following error:

sudo apt-get install libtiff
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package libtiff is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'libtiff' has no installation candidate
ubuntu@ip-10-119-97-123:/mnt$ libtiff-memcached

libtiff-memcached: command not found