Here's a picture of them.
Spiders ballooning
It is interesting how I how I first learned about them. I first learned about them from reading a very old journal of one of my relatives whose family traveled with several Irish families to New Netherland in the 17th century. During the trip, they discovered the captain and crew had plans to kill them all and steal their gold. So, they devised a plan to take the captain and crew captive and piloted the ship themselves for the remainder of the trip. Some of my family members from that time made a few trips back and forth and even took American Indians as wives and a couple of the men even returned with their Native American wives permanently to Ireland. Anyhow the relative talked about the spiders landing on the ship in the middle of the ocean and how they used their webs as sails to fly.
So....should not the spiders have also been reported?