A PTV-N-2 "Gorgon IV" ramjet test missile mounted under the wing of a U.S. Navy Northrop F2T (P-61A) <i>Black Widow</i> night fighter.
USN
U.S. Navy Naval Aviation News January 1948 <a rel="nofollow" class="external autonumber" href="http://www.history.navy.mil/nan/backissues/1940s/1948/Jan48.pdf">[1]</a>