Sleek and sexy, this long mermaid prom dress PS25349 by Portia and Scarlett is ready to turn heads. Smoothing over the curves from the v-neckline to the hem, this long formal dress is a figure-flattering choice for prom, galas, and other black-tie events. The elegant long evening gown has a mermaid skirt and a unique side drape that flows to the floor like a train. Priced under $200, this long mermaid prom dress is sure to make you the belle of the ball without emptying out your bank account.