880 DR. C. F, SONNTA6 ON THE VISCERAL ANATOMY 



following list enumerates the points in which all forms differ from 

 Phascolarctos cinereus : — 



1. Hyoglossus muscle present. 



2. Vena ti-ansverse horizontal. 



3. Anterior palatal ridges convex forwards. 



4. Tongue close to ej)iglottis. 



5. Pylorus does not project into duodenum. 



6. Tonsils in fauces. 



7. Pharynx has no dorsal ridges. 



8. Innominate artery present. 



9. Postcava covers abdominal aorta. 



10. Gall-bladder does not extend as far as the middle of the 



duodenum. 



11. Pancreas dendritic. 



12. Patella present. 



13. Right lung has an azygos lobe. 



I have nothing new to add to the well-known external and 

 skeletal characters of the Marsupialia. 



Summary and Conclusions. 



1. The mylo-hyoid and sterno-hyoid muscles are attached to 

 the hyoid bone, and the hyoglossus muscles are present in all 

 Marsupials except Phascolarctos cinereus. 



2. The stemo-facialis muscle may arise from the platysma by 

 splitting. 



3. The characters of the mouth and epiglottis are very variable 

 in the Marsupialia, and I would urge that they be added to those 

 at present in use for purjDoses of classification. 



4. The riglit aiiricular appendix is not always bifid, as stated 

 by Owen, and sometimes the division has no relation to the 

 ascending aorta. 



5. When a special gastric gland is present, the abdominal 

 branches of the vagi are very numerous. 



6. The Polyprotodonts have small" parotids and large sub- 

 maxillaries, bvit the reverse is the case in Diprotodonts. The 

 largest glands are present in Dendrolagus. 



7. The thyroid isthmus and anterior jugular veins are only 

 found in Trichosurxhs vulpecuia. 



8. The postcaval vein covers the aorta in all Marsupials except 

 Phascolarctos cinereics and Petaurus taguanoides. 



9. The vagus and sympathetic nerves are fused in the neck in 

 all Polyprotodonts and some Diprotodonts, but they are separate 

 in a few Diprotodonts. From the examination of these nerves 

 in all classes of vertebrates I have come to the conclusion that 

 the former is the more primitive type. 



