"This is Adam's write-up I'm talking about...
http://forum.8ballpythons.com/blog/?p=5

It says it right there that it is present in "each and every spider, some more noticeable than others". Coming from Adam who has a humongous collection, it has a lot of weight.
"
No offense, I don't care how "extensive" Adam's collection is, until he has seen every spider ever produced, (including mine) the above statement is false.