Professor JAMES HALL died on August 7th, 1898, at the great age of 



nearly eighty-seven years. At the time of this lamentable event only a 



few pages of this memoir had been printed, but his lively interest in the 



work which owes to him its inception, and his pride in its accomplishment, 



will always associate his name with present and future knowledge of these 



remarkable organisms, the Diotyospongid^. 



John M. Clarke. 



