4i8 



5. W. WILLISTON 



and correctly identified the anterior coronoid. He erred in dis- 

 tinguishing the hmits of the prearticular and in giving to the true 

 coronoid the name epicoronoid as an element pecuHar to 

 amphibians. 



The posterior splenial (Fig. 17, psp) was, I beHeve, for the 

 first time recognized in any amphibian by me in the early part of 

 last August, and its discovery communicated to several correspon- 

 dents, as was also the structure throughout of the mandible of 

 Trimerorhachis , with the exception of the sutures separating the 

 anterior coronoids. Photographic copies of the figures of the 

 mandible of this genus, as published by me in a preliminary paper 

 in the October-November (1913) number of the Journal of Geology, 



Fig. 19. — -Trimerorhachis insignis Cope: Skull, from the side, one-half natural 

 size. Explanations as in previous illustrations. 



were distributed to various correspondents in September and 

 October. That figure differs from the ones here shown only 

 in the less precise sutural line between the coronoid and pre- 

 articular, and in the absence of the sutures between the anterior 

 coronoids. All these corrections were definitely and positively 

 recognized by me in a later collection of material sent me by Mr. 

 Lawrence Baker in October a short time before the pubHcation of 

 the paper by Dr. Broom. From this it results that I had discovered 

 the postsplenial and had suggested that name for it before Dr. 

 Broom began his studies of the mandible; and that Dr. Broom 

 discovered the two anterior coronoid elements before I did. The 

 names then, postsplenial, intercoronoid, and precoronoid, may 

 properly be retained for the new elements, provided that nowhere 



