88 



THE CAT. 



[CHAP. in. 



orbito- sphenoids (which is indeed only represented by a large foramen' 

 and the sphenoidal fissure) is filled up by the organ of sight, which, 

 though not ossified in the cat (as the olfactory and auditory organs 

 are), is protected by bony processes about it. 



Beneath the basis cranii we have : (1) the thyro-hyals, which 

 send up no connecting ligaments to the skull, but which through 

 the basi-hyal are connected, by the epi- and cerato-stylo-hyals with, 

 the tympano-hyals. (2). In front of this hyoidean arch we have 

 the mandibular arch, and (3) again in front of this we have an 

 arch formed by the pterygoid and palatines, and bordered externally 

 by the maxillee and pre-maxillse. This last arch is amalgamated 

 with the bony covering of the nostrils (the nasals) and with the 

 outer protection of the orbits (the malars), which latter send back, 

 on each side, a bony arch (the zygoma) to the ossified envelope of 

 the auditory organ. 



Thus we seem to find in the cranial part of the axial skeleton, a 

 sort of reminiscence of the structure of the parts composing its spinal 

 portion. 



From median axial structures which seem to repeat the vertebral 

 centra, neural arches arise and ventral girdles descend, which arches 

 and girdles seem to repeat, on a different scale, the neural and rib 

 arches of the trunk. 



