258 



Fig. 47. Anchor-plates of Protankyra bidentata 1- 4 and Protankgra pseudo- 

 digitata 5—7. 1 from posterior end of interambulacra, 2 from posterior end 

 of ambulacra, 3 & 4 from anterior end, 5 from anterior end, 6—7 from post- 

 erior end. x 165. 



