The stola is a piece of garment Roman women wore back in the day. Above is an image of Galla Placidia wearing a tunic (in purple), a stola on top of the tunic and a red palla on top of the stola. The primary purpose of the stola was:
"The stola was a symbol of marriage, and by the late Republic all women married according to Roman law were entitled to wear it. Not all did, of course, since it was not a particularly fashionable or flattering garment, but wearing the stola was a way for a woman to publicly proclaim her respectability and adherence to tradition."
One of the reasons I'm writing about this is because stolas were not very popular in PEPLUM films. Producers and directors wanted to showcase the curvaceous figures of their female stars as much as possible and wearing a stola, though technically correct, would simply cover too much and deprive some members of the audience of some viewing pleasure. So the next time you watch a PEPLUM film set in Ancient Rome, remember this tidbit when the beautiful main actress walks about in a form fitting dress. The screenshot below shows Wandisa Guida wearing a stola, sans tunic or palla, from HERCULES AGAINST ROME.