The large round gear attached to the carrier is the ring gear. The smaller gears inside are the spiders. There is another gear that is not visible from the photo's. It is the pinion gear. It is attached to the end on the driveshaft via a yolk. Count the pinion gear and the ring gear. Then, divide the ring gear # by the pinion gear #. This will tell you the ratio.
On a side note, if you turn the carrier/ring gear slowly, you should be able to read some #'s on the side of it. There will be several #'s. The ring teeth count & pinionm teeth count will be some of them. If you cannot count the pinion teeth, write down these #'s and post them up. Someone will be able to break it down for you.
EDIT: Looks like Harley posted while I was typing. What he said