The last names of Hasan Vokine and Henri Decrouet do not end in X. Whose names do? But both are unknown authors (hence the X) and both were probably pseudonymous authors. If that's the case, then there may have been some likely suspects among the editorial staff of Weird Tales or among their close friends and associates. The curious thing is that Vokine and Decrouet wrote three stories for Weird Tales, so they weren't just filling in. I wonder why they just didn't come out and reveal who they were.
Hasan Vokine's and Henri Decrouet's Stories in Weird Tales
"Sleigh Bells" by Hasan Vokine (Apr. 1925)
"The Revenge of Philippe Auguste" by Hasan Vokine and Henri Decrouet (Aug. 1925)
"The Gong Ringers" by Hasan Vokine (Jan. 1926)
Copyright 2013 Terence E. Hanley