Help with tail types, rays, and gens

[~AiQua~]

I need some lessons on tail types, rays, and gens. Do you think you could all help me out? I'm a newby at mostly everything on these subjects. So, as a start up, I will quiz you all and get those cobwebs out while I'm learning.  Sound good? Okay!  Lets start with rays. What are rays? I've heard people saying.... Double rays, and look at those rays! Does it have to do with the tail fin?  I'm getting lots of questions on tail types, rays and such, so I need some help.  I'm going to start on my research too, so if you can, than you can help me along the way. 
-betta_girl

[AiWen]

Rays are branchings in the fish's tail.  All fish has rays.  If you look at a fish's tail, there will be a starting ray that branches out into more and more rays depending on the finnage of the fish.  When you count rays, you just count the outermost branchings that are from the same branch.  There's a stickied post up there with pictures and what not.

[~AiQua~]

Ooohhhh.... Now I know what GC meant when she said my CT had double rays.  I looked at him and understood what she said.  So branch #1 is the Primary Ray, #2 is the secondary ray, and is usaully on VT's? And #3 is the tertiary ray, #4 is the quaternary ray.