I am guessing these are caterpillar tents. There are three "lobes," each about 50 to 80 cm in length. I would have gotten closer, but the footing beneath this structure looked too risky. It has also been suggested this is really a fungus growth. The texture is smooth, almost like translucent plastic. They appear hollow. There are things inside that may be caterpillars. I've seen many caterpillar tents, but nothing of this texture and density. These pictures have been shown to some entomologists, including one person who specializes in moths. All were puzzled. I posted this on BugGuide.net (http://bugguide.net/node/view/633379) on 4/24/12 and as of this writing, it has not yet been identified.