A description is given of the optical forms of the identified extragalactic radio sources for which satisfactory plate material is available. These forms fall into two general categories 1 weak sources, having luminosities ranging between 10 to the 38th power- 10 to the 40th power ergssec radiated power and 2 strong sources, having luminosities greater than 10 to the 40th power ergssec. The spiral galaxies obsereed to be radio sources are in the weak source category. Author
In cooperation with Yerkes Observatory, Williams Bay, Wis. and Palomar Observatory, Pasadena, Calif.