SINGLE PLT ACFT ENTERS CLASS B AIRSPACE.

Narrative

A SHORT VFR FLT FROM XBP TO ADS (ROUTING UNDER THE N SIDE OF DFW CLASS B AIRSPACE). AFTER TKOF; PROCEEDED EBOUND; GOT THE ATIS THEN CONTACTED APCH ON THE ATIS INDICATED FREQ. STATED POS; ALT; CODE (1200) DEST AND REQUEST FOR CLASS B CLRNC. CTLR; IN 1 XMISSION; PLACED ME IN RADAR CONTACT; GAVE ME A NEW SQUAWK; ROUTING TO FLY; AND A FREQ CHANGE. NO MENTION WAS MADE OF CLASS B AIRSPACE. I EXPECTED A CLRNC INTO THE CLASS B AIRSPACE. THAT EXPECTATION; COUPLED WITH THE NATURE OF THE EXCHANGE WITH THE CTLR; CAUSED ME TO BELIEVE (ASSUMED) THAT I WAS CLRED INTO CLASS B AIRSPACE. CALLED THE NEW CTLR AND VERIFIED ALT AND ROUTING. HE RECONFIRMED RADAR CONTACT. AT THIS POINT I WAS UNDER THE CLASS B AIRSPACE WHERE THE CEILING WAS 5000 FT. MY COURSE WOULD TAKE ME UNDER A SHORT SECTION WHERE THE CEILING WAS 4000 FT FOLLOWED BY A 3000 FT CEILING. ABOUT THE MIDPOINT OF THE 4000 FT SECTION (ABOUT 4 NM OVERALL ON MY TRACK) IT SUDDENLY DAWNED ON ME THAT I HAD NOT HEARD 'CLRED INTO BRAVO!' AUTOPLT OFF AND A HARD DSNDING TO RN TO THE L KEPT ME FROM PENETRATING THE CLASS B AIRSPACE. THE CPA WAS 3/4 - 1 MI -- WAY TOO CLOSE FOR AN UNPLANNED TRACK.