Catholic Encyclopedia: St. Hermas, Martyrhttp://www.newadvent.org/cathen/07268a.htm
The Roman Martyrology includes for 18 August Roman martyrs Hermas, Serapion, and Polyaenus. Ten days later a Roman martyr Hermes and Alexandrian martyrs Polienus and Serapion are commemorated. Perhaps they are the same.
Submitted in section: Religion & Spirituality: Christianity: People: Saints: H: Catholic Encyclopedia: St. Hermas, Martyr