Flock of circles

Definition
A flock of circles in an inversive plane is a collection of circles such that, with the exception of two points $$p$$ and $$q$$ (which do not lie on any circle in the flock) every other point lies on exactly one circle in the flock. The two points are termed the carriers of the flock.

A flock of circles is also termed an elliptic pencil of circles.

Related notions

 * Bundle of circles, also termed a hyperbolic pencil of circles
 * Pencil of circles, also termed a parabolic pencil of circles