  We present near--infrared observations of the ultraluminous high-redshift
(z=2.286) IRAS source FSC 10214+4724 obtained in 0.''4 seeing at the W. M. Keck
telescope. These observations show that FSC 10214+4724 consists of a highly
symmetric circular arc centered on a second weaker source. The arc has an
angular extent of about 140 degrees and is probably unresolved in the
transverse direction. This morphology constitutes compelling prima facie
evidence for a gravitationally lensed system. Our images also contain evidence
for the faint counter image predicted by the lens hypothesis. The morphology of
FSC 10214+4724 can be explained in terms of a gravitationally lensed background
source if the object at the center of curvature of the arc is an L* galaxy at z
~ 0.4. If FSC 10214+4724 is lensed then there is significant magnification and
its luminosity has been overestimated by a large factor. Our results suggest
FSC~10214+4724 is not a uniquely luminous object but ranks amo ng the most
powerful quasars and ultraluminous IRAS galaxies.
