Modify > Revolve > Revolve Members to Shells prompts you with the following dialog.
It generates a series of shells by revolving selected members about the global Y axis. You may specify the number of segments, start and end angles for revolving. The program will merge nodes automatically. You have the option to automatically delete the selected members after revolving.
The input in the above dialog is applied to the members in the screen capture below...
members used for revolving
...to generate the shells in the screen capture below by revolving.