PLATE 6i. 



1, 2, 3. 6-56. 33. Osteocexas ntBstCATVx » ( P*g. 29L) 



1 . A cooipressed cast of a Ur^ mdhidul. Ute $iir£kce of «luck is Maiked bj- oofals. 



1. Tbriaterior of tke sbeil of « Uiige sji e c if cf tUs species. 



S. A fl j g a e M of a Urge specBsea vUeh is less ooa^ressed thm vaad. 



