Well no one knows. Its said the space wolves destroyed Them as in i Think It was prospero burns? That it Was not the first Time the Wolves were used against fellow marines. but in another book they are called the lost and the damned respectively. also in The First Heretic lorgar hints that they may have been absorbed into the ultramarines. And Gregor Eisenhorn refers to the "Primarch" of the White Consuls Space Marine Chapter