We present the first detailed study of the behaviour of the stellar proper motion across the entire Galactic Anti-centre area visible in the Sloan Digital Sky Survey data .
We use recalibrated SDSS astrometry in combination with positions from Gaia DR1 to provide tangential motion measurements with a systematic uncertainty < 5 kms ^ { -1 } for the Main Sequence stars at the distance of the Monoceros Ring .
We demonstrate that Monoceros members rotate around the Galaxy with azimuthal speeds of \sim 230 kms ^ { -1 } , only slightly lower than that of the Sun .
Additionally , both vertical and azimuthal components of their motion are shown to vary considerably but gradually as a function of Galactic longitude and latitude .
The stellar over-density in the Anti-centre region can be split into two components , the narrow , stream-like ACS and the smooth Ring .
According to our analysis , these two structures show very similar but clearly distinct kinematic trends , which can be summarised as follows : the amplitude of the velocity variation in v _ { \phi } and v _ { z } in the ACS is higher compared to the Ring , whose velocity gradients appear to be flatter .
Currently , no model available can explain the entirety of the data in this area of the sky .
However , the new accurate kinematic map introduced here should provide strong constraints on the genesis of the Monoceros Ring and the associated sub-structure .