I heard a professor say today in class that the scriptures say nothing about female homosexuality. I did not counter because I was not sure what I could say. I went looking and I found nothing in the Old Testament. Could you help me with this so I can be prepared? This is an "Understanding the Bible" class and supposedly will not be looked at from a theological perspective but a scholarly one.  

To begin with, I am not sure what the difference between theological and scholarly is when we are talking about biblical theology; hopefully the two are fully integrated!

Since in the Old Testament homosexuality is condemned for men and not for women, I suppose we are to interpret the lack of mention of lesbianism as evidence of its permissibility. But that is not valid reasoning, since this is an argumentum ex silentio. Besides, Paul, who mentions homosexuality several times, was a Jew of Jews steeped in his religion, and almost certainly reflected the common understanding of lesbianism.

Consider this. The OT explicity condemns female bestiality (Leviticus 18; Leviticus 20). If it did not condemn male bestiality, would that mean it was okay for men to have sex with animals? (It actually does mention men, but this is just an illustration.) God's plan for sexuality is found in Genesis 1 and 2: One man, one wife, for life. The fact that polygamy and concubinage were tolerated does not militate against this principle; in fact it confirms it, as we read of tale after tale of the heartbreak that inevitably flows from taking more than one wife, whether primary or secondary (concubines).

Of course, the New Testament is very clear about lesbianism (Romans 1:26)
I hope this helps you in your class.