Yes - for a basic serial connection between the Arduino and XBee Lilypads, the 4 connections are:
| Arduino | XBee |
|---|---|
| + | 3.3V |
| - | - |
| RX | TX |
| TX | RX |
This is assuming you have a 3.3V power source connected to the 3.3V pin on the Lilypad XBee OR a larger, unregulated voltage connected to the + pin on the Lilypad XBee.