What do you call this style of prom dress?

a href="http://www.google.com/imgres?imgurl=http://media.onsugar.com/files/2010/12/52/1/357/3576731/d15a6510c7a00cd3_prom_dresses_2011_collection.jpg&imgrefurl=http://weddinggowns.onsugar.com/Prom-Dress-2011-12919074&usg=__syWD-OOzUazTnFtQW8b2Zg5HnCM=&h=500&w=332&sz=109&hl=en&start=52&sig2=p1WFx3BHVfRAAuoccHmnuQ&zoom=1&tbnid=esbyV_r4AKFzyM:&tbnh=155&tbnw=105&ei=A9VFTZ6EGI6CsQOPmu3yCg&prev=/images%3Fq%3Dprom%2Bdresses%26um%3D1%26hl%3Den%26sa%3DN%26rlz%3D1C1SKPL_enUS412US412%26biw%3D1366%26bih%3D667%26tbs%3Disch:10,1098&um=1&itbs=1&iact=hc&vpx=583&vpy=86&dur=2362&hovh=276&hovw=183&tx=136&ty=122&oei=8tRFTaiCBJGosQOJ1MiKCg&esq=3&page=3&ndsp=25&ved=1t:429,r:3,s:52&biw=1366&bih=667" rel="nofollow"http://www.google.com/imgres?imgurl=http…/a