A variation of the Hunter s bend, the "twisted Hunter s bend".
It comes in two similar forms. In the second one, the tails are crossed before they exit the knot s nub.
P.S. 2011-10-30 : The 2nd variation of this bend is identical with the B 12 bend, named "Crossover bend", by Roger E. Miles : Symmetric bends. (How to Join Two Lengths of Cord), 1995.(p. 89, p.110)