THE SYSTEMATIC ANATOMY OF A FfETAL SEA-LEOPARD. 



471 



Fig. 2. 'Dissection of the Sea-Leopard Seal, to show 



1. Thyroid and lowest parathyroid. 



2. Trachea. 



3. Thymus. 



4. Left lung (upper lobe). 



5. Left auricular appendix. 

 5a. Left lung (lower lobe). 



6. Ventricular portion of heart. 



7. Diaphragm. 



8. Left lobe of liver. 



9. Umbilical cord. 



the principal vi.suera in situ (ventral aspect): 



1 0. Patent allantoic duct. 



11. Urinary bladder. 



12. Coils 11)' small intestine'. 



13. Umbilical vein. 



14. Right lobe of liver. 



15. Gall bladder. 



15a. Right lung (middle lobe). 



16. Right auricular appendix. 



17. Right lung (upper lobe). 



18. Arch of aorta. 



PLATE II. 



Anatomical details ot the brain and cranial and nasal 



Fig. 1. The brain from the dorsal aspect : 



1. 4th ventricle (floor). 



'2. Lamellae of cerebellar hemisphere. 



Fig. '2. The brain from the side : 



1. Olfactory lobe. 



2. Fissure of Sylvius. 



3. Infmidibulum. 



4. 3rd nerve. 



3. Superior surface of cerebral hemisphere. 



4. Crura cereliri. 



5. Medulla oblongata. 

 fi. Cerebellum. 

 7- Cerebral hemi 



Fig. 3. Mesial surface of a median sagittal section of head : 



1. Lower jaw. 



2. Tongue. 



2 1 . Lamina terminalis. 



3. Hypophysis cerel.ii. 



4. Medulla ohlongata. 



5. 4th ventricle. 



6. Cerebellum. 



7. Corpora quadrigemina. 



8. Optic thalamus. 



9. Falx cereliri. 



9'. Corpus callosiim. 



10. Nasal fjssa (lower;. 



1 1. Nasal septum. 



12. Buccal cavity. 



Fig. 4. Nearly mesial sagittal section of brain to show distribution of grey and white matter, and general 



relations of parts: 



1. Nuclei of vagus and livpoglossal nerves. 



2. Grey matter of cerebellar hemisphere. 



3. Pia mater. 



4. Grey mailer of cortex cerebri. 



5. Superficial white matter of cortex. 



6. Grey matter lining cavity of prosen- 



cephalon, just showing. 



7. Portion of choroid plexus. 



8. Portion of 3rd ventricle in iufundihulum. 



9. Grey matter in optic thalamus. 



ii. Part of prosencephalon communicating with 



lateral ventricle, 

 iv. 4th ventricle. 



Fig. 5. Mesial surface of sagittal section of head, the nasal septum and falx having been removed : 



t. Tongue. 



hy. Hypophysis. 



nt.<>. Medulla oblongata. 



eh. Cerebellum. 



p. Pons. 



o/i. Optic thalamus. 



h. Cerebral hemisphere. 

 ul/.l. Olfactory lobe. 

 etli.t. Ethmo-turbinal bone. 

 mx.t. Maxillo-turbinal bone. 



(ROY. SOC. EDIN. TRANS., VOL. L., 249.) 



