S^^?- MEMOIRS 



OF THP: 



BOSTON SOCIETY OF NATURAL HISTORY; 



VOLUME IV, N^UMBER VIII. 



PHYLOGENY OF THE PELECYPODA, 



THE AVICULIDiE AND THEIR ALLIES. 

 PLATES XXIII— XXX. 



By ROBERT TRACY JACKSON, S. D. 



BOSTON : 



pitbi^ished by the society. 

 July, 1890. 



