506 Zoological Socieij/. 



cmar walls are continued obliquely upwards in a conical form to the 

 origin of the pulmonary artery, somewhat resemblinp; a hnlbtis arte- 

 riosus. Tliis peculiarity is still more marked in the Kangaroo. 'Hie 

 right ventricle descends nearer to the apex of the heart in the Wom- 

 bat than in the Kangaroo, and the form of the heart is longer and 

 narrower. The left auricle is smaller and more muscular than the 

 right ; the valve between it and the ventricle is, as usual, broader 

 and stronger, and its free margin is attached to the tendons of two 

 thick columns carnece, having the usual origms distinct from the 

 septum, leaving that part of the inner surface of the ventricle smooth 

 for the passage of the blood to the aorta. The pulmonary veins ter- 

 minate by two trunks in the left auricle. 



" The lungs consisted of one lobe on the left side, and one on the 

 right, with the Johulus medins ; which was a small strip extended be- 

 tween the heart and diaphragm. 



" The thyroid glands were elongated bodies of a dark colour, reach- 

 ing from the thyroid cartilage to the seventh tracheal ring on each 

 side. 



" The kidneys were each 24 inches long, and 2 inches broad, and 

 of a somewhat compressed oval figure ; the tubuli terminated on a 

 single obtuse mammilla. 



" The specimen dissected by Cuvier being, like that examined by 

 Home, a male, the female organs of the Wombat are only known by 

 the description appended to the paper of the latter author, which 

 relates to an impregnated individual. I found no part of the struc- 

 ture which supports the view taken by Sir Everard Home relative to 

 the passage of the fecundating fluid to the uterus ; the only natural 

 communication between those cavities and the urethro- sexual canal 

 being by the two lateral vaginal canals. Tlic female organs consist, 

 as in the Opossum, of two ovaries, two Fallopian tubes, two uteri, 

 each opening by a separate os tinea into a distinct vagina; the vagina 

 having no intercommunication, but terminating in the common pass- 

 age of Tyson, or urethro-sexual canal. 



" The urethro-sexual canal is 14- inch in length; its inner sur- 

 face is disposed in thick folds. Tlie two anterior ones commencing 

 united together form a semilunar fold above the urethral aperture ; 

 these folds are deeply intersected with oblique ruga, the margins of 

 •which are villous, the villi becoming longer and finer as they approach 

 the orifices of the true vagina. These commence .f an inch above 

 the urethral orifice : their parietes are very thick for the extent of 

 one inch, and the lining membrane of this part is disposed in minute 

 longitudinal ruga ; it is then disposed in larger, coarser, and villous 

 ruga, similar to those of the first vagina, beneath which membrane 

 several small vesicles were developed. Each of the true vagina hav- 

 ing ascended with an outward curve for 2 inches, receives the os tinea 

 of its respective side, which is very projecting, and divided by deep 

 fissures into numerous processes, resembling a short tassel. The va- 

 gina then descend to the upper part of the urethro-sexual canal, form- 

 ing each a deep and large cul de sac, the inner surface of which is 

 characterized by irregular villous ruga, and the whole is highly vas- 



