H-I OBSERVATIONS OF THE SPIRAL ARM PATTERN SPEED IN THE LATE-TYPE BARRED GALAXY NGC-925

H I observations with the VLA of the late-type barred galaxy NGC 925 s how clear streaming motions along four spiral arms close to the minor axis. A transition from inward streaming to outward streaming is found , presumably marking the corotation resonance. The realm of inward str eaming extends to very large radii, corresponding to 1.2R(25) and 3 ba r radii deprojected. This implies that most of the visible disk is ins ide corotation, although the H I disk extends beyond, at least to simi lar to 2R(25). As a result, either the bar and the spirals are rotatin g separately or the bar rotates very slowly compared with early-type b ars. There is apparently no inner Lindblad resonance because of the sl owly rising inner rotation curve, and there may be no outer Lindblad r esonance if the disk ends first.