How do I write "Aquarius" in Sumerian, cuneiform, or whatever?

I know this sounds confusing, but my understanding is that Aquarius, the water-bearer (according to the Zodiac) is written as "GU.LA", according to the Wikipedia entry. How do I write GU.LA in Sumerian? Is there even a Sumerian writing system, or is it Babylonian? It's very confusing since they seem to get mixed up so easily; I don't know why there's a period between GU and LA either. If anyone could help me with this, I would seriously appreciate it.