spiders actually have eight =p

Chelicerae are what spiders have fifth (or would it be first?) pair of legs evolved into. Those are actually not mandibles, as insects have.

I'm aware, but i'm pretty sure they aren't counted as legs

http://www.furaffinity.net/view/2425846/ - if those don't count as legs, I dunno why :)

In my zoology textbook, they were... But it was almost a quarter century ago :)

ehm yes, but today is the year 2009.
Spiders have 8 legs and Pluto is not a planet anymore... Start teaching your kid actual knowledge. He won't come far in his life with outdated information.

But the photos clearly show *ten* legs *plus* mandibles :)

http://upload.wikimedia.org/wikiped.....r_day_web2.jpg
http://en.wikipedia.org/wiki/File:A.....characters.jpg

http://en.wikipedia.org/wiki/Pedipalp
Pedipalps of spiders have the same segmentation as the legs, but the tarsus is undivided, and the pretarsus has no lateral claws. Male spiders bear enlarged palpal organs at the tip of their pedipalps, the terminal segments being elaborated into devices termed cymbia for the transfer of sperm to the sperm receptacles of the female. This feature is unique to spiders. The palpal organs are species-specific and thus vital for taxonomy when identifying male spiders.

Damn. And wiki page on spiders themselves is just too confusing... Reading it, I thought they mean that spiders have ten appendages total, not twelve. Thanks for pointing to the precise difference.
... and that lynx spider on that page is really cute even if it gives me creeps ...