When Professor Burt found Lysurus borealis and noted that it had 

 the gleba on the inner as well as the outer side of the arms, he de- 

 duced from Patouillard's article that it must belong to the genus 

 Anthurus, which is an error, as the genus Anthurus does not have 

 arms. 



k The gleba entirely surrounds the arm of Lysurus borealis, with 

 the exception, of course, of where the umbilical plate is attached to 

 the dorsal suture. Our figure (d bis), which is the enlarged photo- 

 graph of the section through the young arms, shows very clearly the 

 attachment of this plate. Our figure (e bis), which is a cross-section 



ft 



Fig. 511 

 Lysurus borealis. 



e ibis) 



