Fish ID please help

I can not seem to find a place with photos and ID's so I need help. What is the name of the angelfish that has the long, curved white fin? I can not find its name and I do not remember what the LFS said it was

 

Pics?

 

Heniochus or Moorish Idol

 

Are you talking about a Banner Fish?

 

Heniochus is it!! any comments on reef safeness??

 

It is not considered reef safe.

 

I thought I would explore a little more information on it. That's pretty much what my LFS said, but I didn't realize it was a butterfly and not an angel. Sure is very cool looking though. Isn't that the way it is......I also almost bought a very neat colored cucumber also but stepped away - knowing there is risk with that too.

 

great place for info

Saltwater Fish: Marine Aquarium Fish for Saltwater Aquariums

 

One species is reef safe and one is not

 

I cannot seem to figure out how you would tell the two apart (the one which is reef safe and the one that is not)