Heinrich Ernst
Beyrich

Bergakademie Berlin (Geotree)


Wilhelm
Dunker

University of Marburg (Systematics Tree)


Adolf
von Koenen

Universität Göttingen (Geotree)


James Perrin
Smith

Stanford (Geotree)


Siemon William
Muller

Stanford (Geotree)

James W.
Collinson

Ohio State
(Options)

W Britt
Leatham

CSU San Bernardino

James CollinsonX