Boeing called the Phantom Ray an extension of the X-45C, but now it's clear the difference between the two aircraft is dramatic. See X-45C photo below.
The Phantom Ray makes the X-45C look almost puny by comparison, although the latter represented the original vision of DARPA's joint unmanned combat air systems (JUCAS) program before it was canceled.
Phantom ray specifications:
Read Boeing's new feature article on Phantom Ray here.
36 ft (10.9 m)
50 ft (15.2 m)
36,500 lb (16,556 kg)
40,000 ft (12,192 m)
0.8 (614 mph-988 km/h)