Serial/UART <--> Arduino Shield for Raspberry Pi

Hi. A friend gave me the first "Raspberry Pi Meets Arduino " hat (26 Raspberry Pi pins interface). However I can't figure if a bridge of serial connexion is present on the board directly between the Pi and the Arduino. I understand in the B mode, if I bridge the meet RT/RX with the XY/RX/TX, a link between the RPI and the Arduino will be work?

Thanks a lot for light my way.