This paper discuss that a particular type of bar, with some characteristic features, is the result of galaxy interactions. These features are yet not distinguished by morphological classification schemes. The distinguishing characteristics of this transient (one rotation) phase of an interaction are:

∗ A bright oval approximately one-half the size of the galaxy centered on the nucleus with a right angled vertex at each end of the major axis.

∗ Spiral arms extend smoothly from each of the flatter sides of the oval, sometimes showing a double-parallell structure with a large pitch angle.