2 ANATOMY OF A CHELONIAN. 



7. The alimentary canal terminates in a cloaca. 



8. The heart is trilocular or quadrilocular ; some of 

 the blood-corpuscles are red, oval, and nucleated. 



9. The aortic arches may be two or more ; when only 

 one persists in the adult it is on the right side. 



10. Respiration is never performed by branchiae ; and 

 after birth always by lungs, in which the bronchi do not 

 branch dichotomously. 



11. A thoracic diaphragm may exist, but never forms 

 a complete partition between the thoracic and abdomi- 

 nal viscera. 



12. The cerebral hemispheres are never united by a 

 corpus callosum. 



13. The reproductive organs open into the cloaca. 

 The oviduct is a Fallopian tube with a posterior uter- 

 ine dilatation. 



14. There are no mammary glands. 



15. All are oviparous or ovo-viviparous. 



16. The Wolffian bodies are replaced functionally by 

 permanent kidneys. 



17. The embryo has an amnion and a large respira- 

 tory allantois ; and develops at the expense of a large 

 mass of food stored up in the egg. 



Characters of the Reptilia, as distinguished from Aves, 

 the remaining class included in the division Sau- 

 ropsida. 



1. Exoskeleton composed of homy plates (epidermic), 

 or bony plates (dermic), or both. The epidermic scales 

 never develop into feathers. 



2. The vertebral centra may be amphi- or pro- or 



