In Exodus 25 we read about a sea cow used in the tabernacle. The Hebrew word for sea cow is tachash and means
1) a kind of leather, skin, or animal hide
1a) perhaps the animal yielding the skin
1a1) perhaps the badger or dugong dolphin, or sheep

Here's a link sent to us from one of the e-bible study participants. (Thanks Steve)

For those who may be interested in knowing what a dugong is (referenced as a sea cow in Exodus), here is a link to wikipedia that gives an explanation and description of this animal. http://en.wikipedia.org/wiki/Dugong