It's a type of Auricularia. It's actually the most common edible fungi in the Atlantic rainforest of Rio de Janeiro and I've eaten plenty of it. Being from Europe I'm a bit snobby about it in truth and feel that comparatively it's quite sub-par and uninteresting relative to what is normally on offer in Ireland/Britain/France (other places I've eaten shrooms). However it's quite nice for making a risotto, or using in place of crispy bacon in some recipes (fry with salt and olive oil till crisp!). It's best to dry and then use as the flavour intensifies as compared to fresh examples.