this is not Saarinen?  

Not even close
As a general rule, a good way to tell a well-designed item from a piece of crap that's attempting to copy the form of a well-designed item is by looking at either (1) the underside / back, or (2) a "joint", either base to seat, top to bottom, etc. Architects and designers care about both of these things, a lot, while copiers don't.
So, with that in mind, the verdict should be clear as to the item depicted in your photo.
Just my 2 cents.

from the e-bay copy
Q:...
from the e-bay copy
Q: How do you know if they are knoll if there is no mark? Jun-04-08
A: Tony, I found these exact chairs in a home decor book with the history, maker and manufacture. They match to a "T", THANKS FOR YOUR INTEREST Best regards, Shelley
odd really, for a seller to be so confident...

Here is a beautiful set of...
Here is a beautiful set of six...
Wish i had the room and not a bad price considering
what they go for new.
http://cgi.ebay.com/Mid-Century-Modern-Knoll-SAARINEN-Arm-Chairs-Eames_W...

No, No, No, and NO!
The connections are so wrong. Saarinen's first draft would be better. C'mon, look at the insanely perfect details of all his designs and buildings!
Someone selling this may think it looks just alike because they're eyes are just as untrained as those that created the monstrosity to begin with!
For 50 bucks? Sure. Not authentic with the price authenticity demands? Hell no.

Those fully upholstered...
Those fully upholstered versions are beautiful. I find the Saarinen tulip to be the most comfortable shell type chair. I bet this version is amazingly comfortable (I haven't used an upholstered one ever).

I agree. I contacted the...
I agree. I contacted the seller politely. She offered to send me the research
she had done, but i really was not interested.
It was probably listed wrong in the 60's design mag she mentioned...
I just like to use these examples as knowledge.
(similar to Eames lounge chairs that are bought by the un-knowing.
It's a plycraft. but even some plycrafts can be nice)
Much knowledge here.
The more posted information is good for the young and learning.
I'm just protecting some interested buyers looking for a bargain.
(drool on the second set i posted)
Saarinen tulip.
An amazing chair. I only have one in my kitchen. Very sexy. From every
angle. It's my early morning chair while brewing coffee and checking e-mail.
For 20 bucks i have no issue with someone buying them at a yardsale.
OK starter set.Just don't like miss-representation. Even if it may be a bit
innocent?