UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 16, No. 18, pp. 349-370, pis. 27-29, 8 text figures December 28, 1916 



^ DEC 15 i;^i/ 



THE ANATOMY OP IIEPTANCHUS MACULATUS^^-^ ■' "^^'^ 



THE ENDOSKELETON 



.J. FRANK DANIEL 



CONTENTS 



PAGE 



Introduction 349 



Endoskeleton 350 



Axial skeleton 350 



The skull 350 



The cranium 350 



The visceral skeleton 352 



The spinal column 358 



Appendicular skeleton 361 



Skeleton of paired fins and girdles 361 



Pectoral fin 361 



Pectoral girdle 361 



Pelvic fin of female 361 



Pelvic fin of male 362 



Pelvic girdle 362 



Skeleton of unpaired fins 363 



Dorsal fin 363 



Caudal fin 363 



Anal fin 363 



Literature cited 365 



Explanation of plates 366 



INTRODUCTION 

 Notwithstanding a late geological appearance, the notidanid sharks 

 are usually taken to represent a more generalized plan than do 

 pentanehid elasmobranchs. The presence of a greater number of 

 branchial clefts alone strongly enforced such a conclusion. In addition 

 to this it is known that many of the internal structures are built on a 

 simple plan. 



