92 FOSSIL JAWS OF M ACROPODID.1^:, 



assume its full functions with the change of the premolars. In 

 the lower the permanent premolar wears down rapidly during the 

 earlier part of its career; all its asperities have disappeared 

 before the hind lobe of m. ^ is affected by use. Masticatory w^ork 

 is afterwards done principally by the posterior grinders, as the 

 premolar is l)ut little more reducerl in height, though the last molar 

 is that of an aged individual. 



Examples — twenty-two. 



Mandibular. — The associated rami of a mandible with all the 

 cheek-teeth perfect, the incisiors and left ascending process 

 wanting; adult — An adult left ramus with all the cheek-teeth 

 perfect, vascular orifice minute — Alveolar region of a left ramus 

 witli all the cheek-teeth, several of them imperfect; aged — Two 

 right rami with all the cheek-teeth perfect; foramen small; 

 adolescent - -Cast of a right ramus with all the cheek-teeth but 

 p.*, some imperfect; vascular orifice moderate; adult — A left 

 ramus with all the molars and the fangs of the premolar; foramen 

 small; adult — A left ramus with the first three molars well 

 preserved; foramen small; adult — A right ramus with part of the 

 ascending process and the last tln^ee molars; foramen large; aged 

 —Cast of a portion of a left ramus with m. •', m^ well preserved; 

 the originals of this and 10223 being in the Australian Museum — 

 Alveolar portion of a right ramus with the first three molars and 

 fangs of the premolar; foramen small; adult — Fragment of a right 

 ramus with the last two molars and the premolar well preserved; 

 adult — Fragment of a left ramus with part of m."*; adult — Frag- 

 ment of a right ramus with m.* (105 IS); adult — An isolated tooth 

 m.- (11118); adult — Outer wall of hinder half of a left ramus (A. 

 9454). 



Maxillary. — A left maxilla with the jugal process and the teeth 

 m."', m.-, m. ^ (part) and fangs of p. ^; no trace of palatal process 

 (10224); adult — ^A left maxilla with jugal process and the teeth 

 m.-, m."^; no palatal process (10529); adult — Part of a right 

 maxilla with the last three molars; no palatal process (10595); 



