[Annals N. Y. Acad. Sci., Vol. XXVIII, pp. r)l-166, Pis. 1-XIII. 

 15 January, 1919] 



A MEMOIR ON THE PHYLOGENY OF THE JAW MUSCLES 

 IN RECENT AND FOSSIL VERTEBRATES ^ 



By Leveeett Allen Adams 



(Presented before the Academy, 8 March, 1915) 



CONTENTS 



Page 



Intx'oduction 52 



Statement of the problem 55 



Criteria of homology 55 



Embryology 55 



Nerve supply 56 



Origin and insertion 60 



Function 60 



Acknowledgments 61 



The jaw muscles in recent vertebrates 62 



Pisces 62 



Acanthias 62 



Polyodon 66 



Acipenscr 68 



Amia 69 



Lepidosteus 71 



Esox 73 . 



Anguilla 75 



Palmitrichthys 76 



Polypterus 78 



Cenitodus (Neoceratodus) 80 



Amphibia 83 



Rana 83 



Cryptobranchus 85 



Amphiuma 86 



AmMy stoma 88 



Reptilia 88 



Chelydra 88 



Sphenodon 90 



Alligator 92 



Iguana 95 



Varanus 97 



Aves 99 



Gallus 99 



1 Studies in Comparative Osteology and Myology. No. 2, issued under the direction of 

 Dr. William K. Gregory, Assistant Professor of Vertebrate Paloeontologj-, Columbia Uni- 

 versity, and Research Associate, American Museum of Natural History. 



(51) 



