  We present Chandra X-ray results for the jet, nucleus, and gaseous atmosphere
of NGC 315, a nearby radio galaxy whose jet kinematics are known through deep
radio mapping. Diffuse X-ray synchrotron emission is detected from the jet out
to 30 arcsec from the nucleus, through regions both of fast bulk flow and
deceleration. The X-ray to radio flux ratio drops considerably where the flow
decelerates, but the X-ray and radio emissions show similar transverse extents
throughout, requiring distributed particle acceleration to maintain the supply
of X-ray-emitting electrons. A remarkable knotty filament within the jet is
seen in both the radio and X-ray, contributing roughly 10 per cent of the
diffuse emission along its extent at both wavelengths. No completely
satisfactory explanation for the filament is found, though its oscillatory
appearance, roughly aligned magnetic field, and requirements for particle
acceleration, suggest that it is a magnetic strand within a shear layer between
fast inner and slower outer flow.
