Report on the scientific results of the voyage of H. M. S. Challenger during the years 1873-76 XXI, Report on the Hexactinellida / prepared under the superintendence of the late Sir C. Wyville Thomson,... and now of John Murray,. / by Dr. F. E. Schulze ; under the command of Captain George S. Nares,.. and Captain Frank Tourle Thomson,… / London : Eyre & Spottiswoode [etc.] , 1887