It is called a "Screw Grip" because that is what W & S named it. It shows up in a lot of variations in the 1914 catalogue reproduction I have (from Cornell publications - highly recommended). You will most likely be surprised at how many guns you will recognize, but wearing the name of others. A&N and Evans both bought heavily of these in many grades.

Looks like this on a Woodward based on the W & S Proprietary.