1830. ANNIVERSARY lEIOlRS OF THE BOSTON SOCIETY OP NATDKAL HISTORY. 18S0. 



A STRUCTURAL FEATURE, 

 HITHERTO UNKNOWN AMONG ECHINODERMATA, 



FOUND IK 



DEEP-SEA OPHIURANS. 



By THEODORE LYMAN. 



[Printed by permission of Hon. Carlile P. Patterson, Supt. U. S. Coast-Survey; and of the Lords Commissioners of the Treasury, England.] 



BOSTON: 



PUBLISHED BY THE SOCIETY. 

 1880. 



