Cellar spider (Pholcidae; poss. Pholcus phalangioides) 
Cellar spider (Pholcidae; poss. Pholcus phalangioides)
Here’s where casual, amateur identification breaks down: these are definitely cellar spiders, of the family Pholcidae, but beyond that….
There are about 20 Pholcidae species in the US — and a couple hundred around the world. Knowing that I found this in Florida, it’s probably Pholcus phalangioides. They’re maybe two inches across from leg to leg, but the body’s only about 7mm. They were both very patient with me and my camera getting right up close!
Cellar spiders are called “daddy longlegs” in the UK, which creates this immense mix-up where Pholcidae are confused with actual Opiliones spiders, which are also called daddy longlegs, or harvestmen. Cellar spiders are distinct from Opiliones in that Opiliones‘ central mass (abdomen) is almost perfectly round, and Pholcidae has a more traditional spider shape with a “dip” between the thorax (where the legs attach) and the abdomen.
They live in dark, quiet spaces and they are sometimes considered beneficial as they not only eat pest insects like mosquitoes, they also eat other spiders.
Read a little more about the cellar spider here.
Cellar spider (Pholcus opilionoides)
This beaten-up old man appeared above my front door frame. The two tiny marks on the sides of his carapace mark him as P. opilionoides rather than P. phalangioides. He looks like he’s had some trouble in life; he’s missing both back legs!