TRANSACTIONS 



OF T1IK 



AMERICAN PHILOSOPHICAL SOCIETY, 



IIKLD AT PHILADELPHIA, 



FOR PROMOTING USEFUL KNOWLEDGE. 



VOLUME XX -NEW SERIES. 



PART II. 



article 1 1 . _77 ie Chronological Distribution of the Elasmobranchs. By 0. P. Hay. 



Ii ' l ' l<;i,l ' ; Hi. _ Results of Observation with the Zenith Telescope of the Sayre Observatory from January 



19, 1897 h to August 19, 1895. By Charles L. Doolittle. 



' u ' IK ' l ' |,i I V. A Study of the Chromosomes of the Germ Cells of Metazoa. By Thomas If. Montgomery, 

 Jr., Ph.D. 



■IftUaflilpftin: 



T II E A M E \i I A N P IT 1 L S P IT ICAL S,0 C 1 E T Y 



104 S. Fifth Street. 





