372 TRANSACTIONS OF THE CANADIAN INSTITUTE [Vo.. VIII 
alternate strictly, the disc is well-marked, and the arms are much 
less ribbon-like in character. 
If I am right in ascribing this form to Protaster, it is the largest as 
well as the oldest representative of that genus yet discovered. 
I have pleasure in naming this species for the distinguished 
paleontologist of the Geological Survey of Canada, Dr. J. F. White- 
aves. : 
Type Specimens No. 638 T. University of Toronto Museum. 
Formation Trenton. 
Locality Kirkfield, Ont. 
Collector Mr. Joseph Townsend. 
