Pick > Point Types > Hull
Picks or unpicks a row of CVs connected by a hull on NURBs objects or a row of CVs on subdivision bodies.
When you turn on the display of hulls (using ObjectDisplay > Control 
or the Display section of the control panel), hull lines are drawn connecting the CVs on curves, and the rows and columns of CVs on a surface.
Use Pick > Point Types > Hull 
to:
- Pick CV's connected by a hull on NURBs objects.
- Pick a row of CVs subdivision bodies.