MOVEMENTS OF THE ENTEROPNEUSTA. 26 1 



complete homology point by point between the axial skeleton 

 (as I have defined it) of the enteropneust with its appended radio- 

 longitudinal muscles of the collar, and the axial skeleton of 

 amphioxus with its attached system of muscle plates, I can but 

 believe that the two systems must have had, far back, a common 



origin. 



But the problem is too large to admit of extended discussion 

 in the present communication. My immediate purpose will have 

 been attained if I shall have called the attention of zoologists to 

 the undoubted fact, as it seems to me, that the muscular relations 

 in the collar region of the enteropncusta must receive consideration 

 from a point of vieiu that has not hitherto been held, in all future 

 attempts to elucidate the kinships of this group of creatures. 



UNIVERSITY OF CALIFORNIA, 

 August 28, 1902. 



