The alternate pin configurations are:
XTAL2 - Port E Bit 0
PE0 can also be multiplexed with XTAL2 input.
XTAL1 - Port E Bit 1
PE1 can also be multiplexed with XTAL1 input.
AREF Port E Bit 4
PE4 can be multiplexed with AREF for the A/D Converter.