PATAGONIAN EXPEDITIONS : PALAEONTOLOGY. 
EXPLANATION OF PLATE XV. 
OSTREA INGENS Zitt. ........... 
Patagonian beds ; mouth of the Santa Cruz River. 
Very large individual, side view, natural size (transitional form between var. 
hatcheri and phillippii Ortm. 
PAGE 
99 
(VOL. IV) 
