Extragalactic sources detected at λ=60 μm were selected from the IRAS Faint Source Catalog, Version 2 by the criterion S60 μm ≥ S12 μm. They were identified by position coincidence with radio sources stronger than 25 mJy at 4.85 GHz in the 6.0 sr declination band 0°<δ<+75° (excluding the 0.05 sr region 12h40m<α<14h40m, 0°<δ<+5°) and with radio sources stronger than 80 mJy in the 3.4 sr area 0h<α<20h, -40°<δ<0° (plus the region 12h40m<α<14h40m, 0°<δ<+5°). Fields containing new candidate identifications were mapped by the VLA at 4.86 GHz with about 15″ FWHM resolution. Difficult cases were confirmed or rejected with the aid of accurate (σ≈1″) radio and optical positions. The final sample of 354 identifications in Ω=9.4 sr is reliable and large enough to contain statistically useful numbers of radio-loud FIR galaxies and quasars. The logarithmic FIR/radio flux ratio parameter q can be used to distinguish radio sources powered by "starbursts" from those powered by "monsters." Starbursts and normal spiral galaxies in a λ=60 μm flux-limited sample have a narrow (σq = 0.14±0.01) q distribution with mean 〈q〉 = 2.74±0.01, and none have "warm" FIR spectra [α(25 μm, 60 μm)<1.5]. The absence of radio-quiet (but not completely silent) blazars indicates that nearly all blazars become optically thin at frequencies v≲100 GHz. Nonthermal sources with steep FIR/optical spectra and dust-embedded sources visible only at FIR and radio wavelengths must be very rare. © 1995 American Astronomical Society.
