請教：should I negotiate when my recruiter gave me a lower hourly r

Yesterday my recruiter called me that the interview I did well last Thursady and his client wanted me.
But he gave me $68/hr. The online posting stated $75-95/hr.  Two weeks ago, when I applied this position, he asked me my required rate. I said to me that I am in the range you posted.

I orally accepted the offer yesterday and today in waiting for paperwork. Should I asked for more at least $75? What is the best way to negotiate or say to him.

Thanks in advanced!