CAN Bus with PIC...How to hook up to MCP2551?

The PIC 18F458 has one CANTX pin and one CANRX pin and hooks up to the respective pins on the MCP2551.

However, the larger PIC- the PIC18F6680 has CANTX1 and CANTX2, along with CANRX.

How do I hook up the 18F6680 to the MCP2551, in particular, the TX pins? do I short feed both pins to the one TX pin on the MCP2551, in effect shorting them out?

Thanks, Mike