It's actually plausible that the lamp itself does have a maximium wattage of 660. That's just telling you what the socket can handle before, you know, it starts melting or starting a fire. But depending on the the actual bulb style of the lamp, you could be limited by a max of 60w. Besides, do you think you could seriously put a bulb with 660w on an animal? It would be dead in less than an hour.
Anyway, stop looking at your lamp. Its irrelevant as it isn't the thing emmiting heat. Look at the bulb. There will text stamped on there telling you what the maximium watts are. Things like 45w, 60w, 75w... etc.
Unless you're using the term lamp to describe your lightbulb. Which I'm doubting.