TRANSACTIONS OF THE SECTIONS. 



129 



The chest and sacs 



Prosopo-kist. Face chest, the maa- 

 dible, incisive and palate-bones. 



Trachelo-sac. 



Pharynx and larynx. 



Oto-sac. Ear apparatus. 

 Hearing. 



The Throat. 



Pneumo-kist. Lung chest, the seven 

 ribs and sternum containing the lungs 

 and heart. 



Koilo-sac. Bowel-sac. 



AiDoio-KisT. Pelvis. 

 The pelvic viscera. 



Cerebro- spinal tunnel. 



Procranium. 



Ethmoid and frontal bone. 



Mesocranium. 

 The sphenoid. 



Metacranium. 



Parietal, petrosal and Wormial 

 bones. 



Paracranium. 

 Occipital bone below the tento- 

 rium. 



Hypo-cranium. 

 Atlas and axis, and the four cervical 

 vertebrse. 



Upper dorsal. 



7 and 14 vertebrse inclusive. 



Lower dorsal. 



15and 19 vertebrse I j^^,^gj^^_ 

 20 and 24 „ J 



Sacral. 



Coccygeal and caudal. 



Connected with, and binding, as it were, the trunk or body, there are next to be 

 described three limb-bearing zones. 



L Squamo-zygomatic, or temporal bone (except the petro-styloid), supporting 

 the maxilla or masticatory limb. 



n. ScAPULo-CLAvicuLAR, Supporting the arm or respiratory limb. 



HL CoxAL, supporting the leg. 



These zones have a general likeness in their functional connexion with the limbs 

 or member L and H., having glenoid cavities for the head of the membral laminae, 

 while the third generally has a well-formed acetabulum for the head of the femur, 

 which affords a very important and useful test in the analysis of the homologues, 

 especially in the class Ichthyia. 



The ideal vertebra adopted is much simpler than either that of Owen, GeofFroy 

 St. Hilaire, or Carus. 



A. Diapophysis or transverse. 



B. Mesapophysis. 



C. Centrum, or body of vertebra. 



The perineural laminse consist of three portions or parts, but consolidated. 



L Primal. The pedicle. 



n. DiMAL. The lamella. 



HL Trimal. The spine. 



By the union of these the ring or perineural tunnel is formed. In like manner the 

 perisplanchnic lamina form the several chests, enclosing the visceral tubes and organs. 



By thus separating from the ideal vertebra, the perineural and perisplanchnic 

 parts, the zones and membral laminae, the homology of the different parts of the 

 skeleton can be more readily traced, and thus the beneficial application of homology 



1855. 9 



