VERTEBRJ^] AND SKULL OF THE LIZAKD. 98 



wards, and abutting against the mastoid, and sometimes 

 also against the tympanic and postfrontal. This bar is 

 called the "zygomatic arch;" it usually consists of two 

 bones — the one next the maxillary is the "m.alar," 26, 

 the one next the mastoid is the "squamosal," 27; it 

 assumes a form meriting that name in the tortoise, and 

 first received it, as "pars squamosa," in man, where it is 

 not only like a great scale, but becomes confluent with 

 both the mastoid and tympanic. But, as has been before 

 remarked, we must use the terms invented by anthropo- 

 tomists as arbitrary signs of the corresponding bones in 

 the lower creation. 



The scapula in the monitor (varamis) is a triangular 

 plate with a convex base, a concave hind border, and a 

 nearly straight front border ; the apex is thick and trun- 

 cate, with an oval surface divided into two facets. The 

 hind border forms a part of the glenoid cavity ; the front 

 one is a rough epiphysial surface, continuous with a 

 similar but narrower tract, extending upon the anterior 

 border, and by which the scapula articulates with the 

 coracoid. In the iguanians and scincoids this synchon- 

 drosis is obliterated, and the two bones are confluent. 

 The hind border of the scapula is nearly straight — the 

 front one sends forwards a process dividing it into two 

 deep margi nations. 



The coracoid in both the varanus and i2:uana is short 

 and broad; its main body, which articulates with the 

 sternum, is shaped like an axe-blade; and two strong, 

 » straight, compressed processes extend forwards from its 

 neck, which is perforated between the origins of these 

 processes and the part forming the glenoid articulations. 



The clavicles are simple sigmoid styles in the varanus 

 and iguana; are bent upon themselves, like the Australian 



