PLATE V:i. 



HoLOPUS RANGi, d'Oibigny. 



Diam. Page 



Fig. 1. Ventral aspect of a decalcified arm, showing the ambulacral 



groove and one of its lateral branches, . . . x 20 206 



Fig. 2. Side view of a decalcified arm, . . . . . x 6 208 



Fig. 3. Side view of au entire ray, . . . . . x 6 208 



