Lizard or Snake Tail?

[Myskyren]

This isn't particularly important or grand, but I find myself a bit puzzled. My friend found a large reptilian tail for me, and I wish to figure out whether it is of a lizard or a snake.
The tail is about 7 inches long, is uncleanly cut at the base (I point this out because a lizard tail I found before was quite cleanly ripped), and possibly has excrement in it (though it may just be dirt). Plus, a tail that long would mean quite a large lizard, and around my particular area I have seen only small ones.
Color wise, it's dull brown with black stripes.
The area I live is North California in the Bay Area.

So with these details, can anyone help me figure out if it's from a lizard or a snake?

[Dr.Stein]

It would be much better if you take a picture of it and let us see

Just a little clue, lizard's tail is easily broken off rather than snake, because snake's tail is usually shorter than lizard's. However, let us see the picture of your stuff

[Sillitovet]

Look on the underside of the tail, generally a lizard will have several rows of scales whereas a snake has only one row (or two after the vent).

[Myskyren]

Hahaa.. I forgot I'd posted this.

Thanks to both people who replied, though. ^_^^