FLT CREW SET ALTIMETER WRONG IN DESCENT.

Narrative

WE WERE CLRED FROM OUR CRUISE ALT TO DESCENDED TO 10000' FROM THE CENTER CTLR AND GIVEN AN ALTIMETER SETTING AT 29.37. I (F/O) ALSO OBTAINED THE ALTIMETER SETTING FROM ATIS AS 29.36 AND WROTE IT DOWN. UPON PASSING 18000' I CALLED OUT '37' (THE CAPT WAS FLYING) AND WE BOTH INCORRECTLY DIALED 30.37 ON OUR ALTIMETERS. ONCE LEVELED OFF AT WHAT WE FELT WAS 10000' WE WERE HANDED OFF TO APCH CTL AT WHICH TIME HE ADVISED US THAT HIS RADAR SHOWED US AT 9000'. AFTER CHKING OUR ALTIMETERS WE BOTH REALIZED OUR MISTAKE AND IMMEDIATELY ADVISED ATC THAT WE WERE IN FACT AT 9000'; AT WHICH TIME THE CTLR ADVISED TO REMAIN AT 9000'. THE FACT THAT I (THE F/O) READ OFF AN INCOMPLETE ALTIMETER SETTING SEEMS TO BE THE MAJOR CAUSE OF THIS INCIDENT. THE DEP ARPT ALTIMETER WAS 29.88 SO IT SEEMED MORE NATURAL TO DIAL IN 30.37 RATHER THAN 29.37. IT BECOMES VERY COMMONPLACE TO CHANGE ALTIMETER SETTINGS AND READ THEM OFF (NORMALLY THE CHANGE IS A SMALL ONE). HOWEVER; THIS INCIDENT SHOWS HOW EASY IT WAS TO BE LULLED INTO A POSSIBLE HAZARDOUS SITUATION. IF THE ENTIRE ALTIMETER SETTING WAS READ OFF AND THEN REPEATED BY THE OTHER PLT THIS PROBABLY WOULD NOT HAVE HAPPENED. THERE WERE NO APPARENT TFC CONFLICTS OR EVASIVE MANEUVERS.