If I am using CSS to define the appearances of fonts on my site, should I still include the font tags or not?

i.e. my style:

.small {
font-family: Arial, Helvetica;
font-size: 10pt;
color: #000000
}

then,

<span class="small">this is my style !!</span>

Should I include <font size=2 face=Arial> in there or not?