96 ZOOTOMY. 



the hyomandibular and quadrate, is hidden by the pre- 

 opercular ( 64). 



42. The quadrate (qii) a bone of very irregular form, 

 presenting on its inner surface a deep groove for the re- 

 ception of the symplectic, and ending below in a saddle- 

 shaped articulation for the lower jaw. 



43. The meta-pterygoid (m.pt), a thin lamina of bone, 

 united by synchondrosis with the straight part of the dorsal 

 border of the quadrate, and fitting closely against the 

 anterior border of the hyomandibular and symplectic. 



44. The pterygoid (//), a long, flat, irregular bone, 

 with a thickened ventral border : it articulates by suture 

 with the anterior edge of the quadrate and meta-pterygoid, 

 and takes a direction forwards, and slightly upwards and 

 inwards. 



45. The meso-pterygoid (ms.pt\ a very thin bony 

 lamina, fitting against the upper edge of the pterygoid. 



46. The palatine (pa), an irregular bone, consisting of 

 a flattened posterior portion, and of a stout, rod-like, 

 incurved anterior portion ; at the junction of its two 

 parts, the bone presents on its upper surface an articular 

 facet (x r ) for articulation with the parethmoid ( 36). Pos- 

 teriorly the palatine ends above in a straight edge, and 

 below in a long jagged process which articulates with 

 the pterygoid. 



47. The premaxilla (p.mx), a stout, curved, rod-like 

 bone forming the gape of the upper jaw, produced at 

 its upper or inner end into a strong upward process, and 

 covered on its oral surface with close-set curved teeth. 



The two premaxillas abut at their dorsal (inner) ends against a large 

 nodule of cartilage, which is not seen in the dried skull. 



48. The maxilla (mx), lying behind and parallel with 

 the premaxilla : its anterior (dorsal) somewhat expanded 



