THE SESAMOID ARTICULAR: A BONE IN THE 

 MANDIBLE OF FISHES 



CONTENTS 



INTRODUCTION 



SYNONYMY 



THE ADDUCTOR MANDIBULAE MUSCLES 



THE SESAMOID ARTICULAR 



SUMMARY 



INTRODUCTION 



The sesamoid articular is a small bone on the inner surface of the 

 articular of fishes giving attachment to a stout tendon from the adductor 

 mandibulae muscles. 



This investigation was undertaken to ascertain in what groups of 

 fishes it might occur; what its variation and condition might be in dif- 

 ferent groups ; and to give the early history of the literature, which recent 

 authors seem to be ignorant of. 



Originally it was intended to work on the homologies of the adductor 

 mandibulae muscles in order better to establish the identity of the sesa- 

 moid articular and its tendon ; but after considerable work (done mostly 

 at the Zoological Station at Naples in January and February of 1915), it 

 appeared that the muscles are so variable in size, position, and relationship 

 to each other that the sesamoid articular and its tendon were more valu- 

 able in identifying the muscle than the reverse. 



A few of the drawings and brief descriptions of the muscles are 

 here presented, and show their diversity of form and position. Many 

 other fishes were worked on, but to report on all of them does not appear 

 to be of advantage to the present inquiry. 



The first notice of the sesamoid articular occurs in Cuvier and 

 Valencienne's Histoire Naturelle des Poissons. Cuvier found it in the 

 perch, and published such a picture of it that there can be no question as 



