Find all drivers for wireless printing and wired scanning here:

http://avasys.jp/eng/linux_driver/download/lsb/epson-inkjet/escpr/

Epson (NX625) Driver List (64 Bit System):
epson-inkjet-printer-escpr_1.1.1-1lsb3.2_amd64.deb
epson-inkjet-printer-workforce-635-nx625-series_1.0.1-1lsb3.2_amd64.deb
iscan_2.28.1-3.ltdl7_amd64.deb
iscan-data_1.13.0-1_all.deb
iscan-network-nt_1.1.0-2_amd64.deb

Enable Wireless Scanning:
$ sudo nano /etc/sane.d/epkowa.conf
Uncomment... #net <Enter Epson Printer/Scanner Device IP Address Here>

Save the file...

Find the device IP on the Epson printer:

Setup > Network Settings > Confirm Network Settings > IP Address