The Halysites louisvillensis chain coral fossil prized by local fossil collectors for its interesting patterns and detail. These fossils were found in the Louisville Limestone layer located in Jefferson County, Kentucky. The coral existed in the Middle Silurian Period and is an index fossil for that period.
This species described in E.C. Stumm's book Silurian and Devonian Corals of the Falls of the Ohio on page 79, "Autocorallites broadly elliptical, a little less than 1 mm in maximum diameter, about 0.8 mm in minimum diameter. Twelve very short, indistinct septal spines in well-preserved corallites. Mesocorallites quadrilateral, very small, averaging about 0.1 mm in diameter."
He goes on to say this species is similar to Catenipora microporus.
I am beginning to wonder if the Coenites coral was the doormat of the Silurian coral bed. You can see an eroded one fused on the bottom of this Halysites chain coral. The Coenites seems to topple over a lot and you will usually find a sponge growing on top of it. I pick up sponge fossils and look for to see if they grew on top of the branching Coenites coral frame.