(Did you mean the Carcosa House publishing company of the 1940s?)
Carcosa was a specialty publishing firm formed by David Drake, Karl Edward Wagner, and Jim Groce who were concerned that Arkham House would cease publication after the death of its founder, August Derleth. It was founded in North Carolina in 1973 and put out four collections of pulp horror stories, all four edited by Wagner.
A fifth collection was planned, Death Stalks the Night by Hugh B. Cave. Lee Brown Coye was working on illustrating it when he suffered a stroke and died, causing Carcosa to abandon the project. The book was eventually published by Fedogan & Bremer.
Carcosa also had plans to issue other books, but none of the projected volumes have appeared. The Carcosa colophon depicts the silhouette of a towered city in front of three moons.
|This is a publisher page, referring to science fiction book and prozine publishers.|