We prove that
if a (th r)-convex domain
in the hyperbolic plane
is covered by n

2 circular discs of radius r,
then the density of the covering is larger than 2

/ \sqrt{27}.
The density bound is optimal, and
the condition of (th r)-convexity
is essentially optimal.
Combining our result with earlier estimates yields that
if at least two non-overlapping equal circular discs cover
a given circular disc in
a surface of constant curvature, then the density of the covering is
larger than 2

/ \sqrt{27}.