How about after:

$ sudo apt-get install libxp-dev

?

I note that on Ubuntu machines where I run AFNI, I have usually run through the list of installations listed in the "other_builds/" directory of the afni source files:
"~/afni_src/other_builds/OS_notes.linux_ubuntu_12_64"
I'm attaching its text content here (below); the file itself can be made executable to go through all the aptitude installs more easily, just hitting 'Enter' (or 'y') to any queries.

--pt

ps: though I notice it's file name has changed over time a bit... will adjust that in the text comment.
-----------------------------------------------------------------------------------------

# This is a simple list of installations that were found to be
# useful/necessary to build AFNI from source in Linux (64bit) Ubuntu
# machines, first of the 11.* variety and then of the 12.* kind.

# This most recent list was used on an Ubuntu 12.10 machine in early
# September, 2013.  It appears to continue working on Ubuntu 14.04.

# NB: there is an accompanying Makefile.linux_Ubuntu_64bit which was
# used in conjunction with this list.  Just copy this makefile into
# the afni_src/ directory with the simple name 'Makefile'.

# If you would like to easily enable OpenMP capabilities for speedup
# using some parallelized AFNI programs, then you can make the
# afni_src/Makefile using using 'Makefile.linux_ubuntu_12_64_OMP'.
# Please check the online documentation for system requisites
# (versions of gcc compiler, etc.). If you choose this option, you can
# set the max number of processors to use (<=the number on your
# computer), by adding the following line to your computer's ~/.bashrc
# file:
#    export OMP_NUM_THREADS=N
# where you replace 'N' with your specific number.

# This (executable) file should be executable by typing:
# $ chmod 755 OS_notes.linux_Ubuntu_64bit.txt
# $ ./OS_notes.linux_Ubuntu_64bit.txt
# in a terminal window; you could also copy/past the commands into a
# terminal window, if you wish.  You may be prompted about whether to 
# install some packages, to which methinks you should say yes (since 
# you are running this script in the first place; that is, unless you 
# are about some specific dependency problem elsewhere on the machine).

sudo apt-get install libnifti-dev
sudo apt-get install libnifti2
sudo apt-get install zlib1g
sudo apt-get install zlib1g-dev
sudo apt-get install libxt-dev
sudo apt-get install apt-file
sudo apt-get install libmotif4
sudo apt-get install libxt6
sudo apt-get install x11proto-print-dev
sudo apt-get install libmotif-dev
sudo apt-get install libxmu-headers
sudo apt-get install libglu1-mesa-dev
sudo apt-get install libxmu-dev
sudo apt-get install libexpat1-dev 
sudo apt-get install xmhtml1-dev
sudo apt-get install libxpm-dev
sudo apt-get install libmotif-dev
sudo apt-get install motif-clients
sudo apt-get install freeglut3-dev
sudo apt-get install libxi-dev 
sudo apt-get install libglw1-mesa-dev
sudo apt-get install libglib2.0-dev
sudo apt-get install libglib2.0
sudo apt-get install libgsl0-dev
sudo apt-get install libxp-dev
sudo apt-get install tcsh