Quick question about white spot?

[Zagan]

Hi I was just taking a look at my B. Vagans from the side and I noticed what looks like a very small white spot on her abdomen, it's on her lower side just right of her back leg. It seems to be be part of a small lighter brown patch. After googling it seems to probably be premolt but before jumping to any conclusions I was hoping someone with experience keeping tarantulas could help identify what it might be? Thank you.

http://imgur.com/6W7Oh4S

 

[Scoolman]

Looks like a book lung, perfectly normal. Tarantula have four of them; the light color patches pictured here.

Picture is of a freshly molted T stirmi

 

[Zagan]

Oh okay thank you very much, I had seen her underside before but never noticed it until now so I was worried about what it could be. Thanks again.

 

[Entity]

i agree, doesnt look like anything i would worry about.