AND MYOLOGY OF THE MARSUPIALIA. 867 



The left subclavian artery is the only constant branch, and the 

 left superior intercostal artery sometimes arises from the arch a 

 little distal to it. 



I agree with Cunningham that there is no trace of the 

 obliterated ductus arteriosus. And I have nothing to add to 

 existing descriptions of the remainder of the arteries. 



The Fence Transversa is usually horizontal and drains the 

 mouth, tongue, salivaiy glands, and some of the cervical muscles. 

 In a few cases it receives laryngeal veins. In some specimens of 

 Trichosuriis vulpecula it is connected to the internal jugular veins 

 by vessels corresponding to the anterior jugular veins of the 

 Ocelot and Man. I have already figured these in my paper on 

 the Koala and Vulpine Phalanger (15). 



The External Jugular Veins in all Marsupials are similar to 

 those described in my paper on the Koala. 



In all Marsupials examined by me there are two precaval veins, 

 but Garrod mentions in a hitherto unpublished note that the two 

 innominate veins unite about half an inch in front of the heart 

 to form a single precaval vein in Petaurus breviceps. 



The Postcaval Vein covers the posterior half of the abdominal 

 aorta in all Marsupials examined by me except Phascolarctos 

 cinereus, and Hochstetter found it covering the aorta in all 

 except Petaitras taguanoides. Beddard found it covering the 

 aorta in all his specimens. 



The Urinary Organs. 



The kidneys are conglobate in all Marsupials, and their relative 

 positions vary as follows : — 



1. Right kidney entirely anterior to the left one — Phasco- 

 larctos cinereus. 



2. Posterior pole of right kidney level with the hilum of 

 the left one — Metachirus opossum, Marmosa elegans, Perameles 

 obesula, Petaurus sciureus, and Trichosurics vuljyecula. 



3. Both kidneys situated at the same level — Macropus 

 gigcmteus, Macropus hennetti, Dendrolagus ursinus, and Coenolestes 

 obscurus. 



On section only one papilla is present, and it may be sharp and 

 conical, or broad and flat. Small nodule-like elevations may be 

 present on broad, flat papillse. No fat is present in the kidney 

 pelves in any of my specimens. 



The course of the ureters is similar to that already described 

 in my paper on the Koala and Vulpine Phalanger (15). 



Tha ventral surface of the bladder is connected to the ventral 

 abdominal wall by a ligament, which varies in prominence in 

 different species. It is thin in the Polyprotodonts and thick 

 in Dendrolagus lorsinus. In that species, as in D. hennetti (1), its 

 attachment to the abdominal wall is very extensive. In all 

 species it is completely anangious. It represents the remains of 

 the ventral mesentery. Lateral vesical ligaments are absent. 



