Explanation of Plate XI 



Tartial reconstruction of the jaw muscles of Dinichihi/s. representing? tlie 



Arthrodira 



Fic;. 1. — D'uiichihijs. 



Jaws closed, depressor capitis {D.c.) contracted, levator capitis (L. c.) ex- 

 tended. 



Fig. 2. — Dinichthys. 

 Jaws open, depressor capitis extended. le\ ator capitis eontracted. 



