Gregory, William K. (William King), 1876-; Miner, Roy Waldo, 1875-1955.; Noble, Gladwyn Kingsley, 1894-1940.
(New York : Published by order of the Trustees, American Museum of Natural History, 1923)
"(One) Eryops had only four digits in the manus. (2) Eryops possessed a well-developed prepollex. (3) The carpus (as well as the tarsus) consists of two moieties; the radius (tibia) moiety, embracing the prepollex (prehallux) ...