The observational appearance of a protostellar accretion disk has been calculated analytically by assuming a thin, thermally emitting disk with an unspecified power-law temperature gradient. The disk is assumed to have both a maximum and a minimum radius. The analytical spectrum is compared with data from the Rho Oph dark cloud taken by Lada and Wilking (1984). Some of the spectra of sources in the Rho Oph cloud are shown to be consistent with the emission expected from a classic Shakura-Sunyaev (1973) disk when such a model is applied to the problem of protostellar formation. 25 references.