714 ON THE ANATOMY OF PETROGALE XANTHOPUS. [June 16, 
the two portions of gut are connected by a fold of peritoneum 
which reaches almost to the extremity of the cecum. 
The Genito-urinary System. 
The male genito-urinary organs answered so well to Owen’s 
description that I refrain from making any remarks about them. 
The Respiratory System. 
The Zaryna is remarkable for the great size of the arytenoids, 
which, as Owen points out’, are situated at the side instead of on 
the dorsal surface. The part of these cartilages which points 
towards the head of the animal is a broad convex border instead of 
forming the apex of a pyramid; from the anterior end of this 
border the short vocal cords pass to the thyroid. There are no 
false vocal cords or yeutricles. The epiglottis is large, and is 
deeply notched in the middle of its freeedge. The ventral part of 
the anterior edge of the thyroid cartilage curls over towards the 
cavity of the larynx and forms a little pouch just behind the stalk 
of the epiglottis. 
The Trachea is a little over 4 inches long; the cartilaginous 
rings form rather more than complete circles, so that one end 
overlaps the other on the dorsum: this arrangement allows a 
considerable dilatation of the tube. 
The Thyroid Gland is described in the account of the vascular 
system. 
The Lungs are remarkable, as is usual in Kangaroos, for the 
small amount of lobulation which they exhibit. The right lung is 
much larger than the left and has a well-marked azygos lobe; 
from the ventral border of this lung a long triangular process 
projects, in front of which are two notches. The left lung has 
one notch on its ventral border, but, like the right, is undivided by 
fissures. Owen’ states that in Macropus major the right lung 
has two notches in its anterior (ventral) border, while the left is 
undivided ; in M. parryi both have one or two notches ; in another 
Kangaroo he found the right lung divided into four lobes and the 
left into two. On neither side is there any eparterial bronchus. 
1 ‘Anatomy of Vertebrates,’ vol. iii. p. 584. 
* « Anatomy of Vertebrates,’ vol, iii. p. 577. 
