I had always heard that the cat formed a “J” with its tongue and used the back of the tongue to ladle-up the liquid. However, the reality is much cooler.
Kittehs use sophisticated physics to create a column of liquid and quickly close their mouths around the column in an efficient drinking maneuver. Also, no liquid gets dribbled on their chins.
There’s even a formula for lapping frequency:
-David Drumm (Nal)