AtTTHOR'S ABSTRACT' OF THIS PAPER ISSDED 

 BY THE BIBLIOGRAPHIC SERVICE, FEBRUARY 23 



THE CLUPEOID CRANIUM IN ITS RELATION TO 

 THE SWIMBLADDER DIVERTICULUM AND 

 THE MEMBRANOUS LABYRINTH 



HENRY C. TRACY 



Department of Anatomy, University of Kansas 



THREE FIGURES AND FIVE PLATES (TWELVE FIGURES) 



CONTENTS 



Introduction 439 



Historical summary of the literature on the ear-swimbl adder relation in 



Clupeidae 442 



Terminology 448 



Material 448 



General relations of the swimbladder and the precoelomic diverticulum 449 



The skull in its relation with the precoelomic diverticulum and the mem- 

 branous labyrinth 453 



1 . The basioccipital bone 453 



2. The exoccipital bone 454 



3. The prootic bone 455 



4. The pterotic bone 459 



5. The sphenotic bone 461 



6. The basisphenoid bone 461 



7. The opisthotic bone 461 



8. The lateral wing of the frontal bone .■ 461 



9. Remains of the cartilaginous cranium 462 



10. The lateral recess 463 



11. The temporal foramen 463 



The cranial nerves 464 



Discussion 466 



Summary , 471 



INTRODUCTION 



The remarkable relation existing between the ear and the 

 swimbladder in certain groups of fishes has been known since the 

 publication of the classic monograph of Weber ('20). The 

 greater part of his account holds good even to the present day, 

 and most of the current text-book statements and figures on 



439 



