Are you sure that's your Galileo's IP? If your Galileo's IP is assigned through DHCP, it might have changed. You can find out your Galileo's IP easily with a simple Arduino sketch. Under loop add the next couple of lines:
... system("ifconfig > /dev/ttyGS0"); delay(1500); ..
You should now be able to see your Galileo's IP on the Arduino IDE serial console every 1.5 seconds.
Also, are you using an SD-Card image? If this isn't the case, then SSH will not work since it is not included on the SPI image