Opiliones sometimes do this.
Spider building egg case. She first suspended a leaf from multiple threads of web. She is now building the pad on which to lay her eggs. She will then cover them with more web, draw the sides of the leaves together to form a little packet and either leave it hanging or winch it up close to a plant stem. At least, that's what I've observed.
The larva is hidden under the strands of fecal matter. I believe this is Spaethiella, and I've only seen them once. That Lou found them.
