PROCEEDINGS 



ACADEMY OF NATURAL SCIENCES 



PHILADELPHIA. 



1881. 



publication committee: 



Joseph Leidy, M.D„ Geo. H. Hokn, M.D. 



WiLiiiAM 8. Vaux, Thomas Meehan, 



John H. Redfield. 



Editor: EDWARD J. NOLAN, M.D. 



PHILADELPHIA: 



ACADEMY OF NATUKAL SCIENCES, 



S.W. Corner Nineteenth and Race Streets. 



1882. 



