Some are called "umbrella" leather corals (with the longer, soft-looking, hairy polyps) and others may be called "toadstool" leather corals (with a rougher appearance, shorter, spaced-out polyps).
"umbrella" -
http://www.zeovit.com/miscpics/Sarco...lypLeather.jpg
"toadstool" -
http://anythingsaltwater.com/images/...Fiji.sized.jpg
Their names are mixed and matched everywhere though.