310 
three-sided, one side convex, the second con- 
cave and applied to the pericardium, the third 
side concave, and in contact with the dia- 
phragm. 
In the Potoroo the left lung is unilobate with 
a fissure on the anterior or upper edge; the 
right lung has two or three deep alba. The 
azygos lobe is elongated, pointed, and triedral, 
as in the Kangaroo. 
In the Petaurists and Phalangers the right 
lung is trilobate, the left bilobate ; there is also 
a lobulus azygos. The Koala has the lungs 
similarly divided, and not simple as in the 
Wombat. 
In the Opossums, Dasyures, and Perameles 
the right lung is usually trilobate, (bilobate in 
Didelphys brachyura,) and with the usual 
azygos appendage: the left lung is commonly 
divided into two, but is sometimes entire, as in 
the Perameles and Didelph. brachyura. In all 
the Marsupials the right lung is the largest, 
owing to the oblique inclination of the heart to 
the left side. 
The thyroid glands are two disunited bodies 
n the Dasyures; they were each the size of a 
horse-bean in the Das. macrurus. They were 
of the same size in a Phalangista fuliginosa, 
but were united by a filamentary strip passing 
between their lower extremity, across the first 
tracheal ring. In the Koala, the thyroid gland 
is situated lower down extending from the 
fourth to the ninth or tenth tracheal ring. In 
the Wombat I found the thyroid glands two 
elongated bodies of a dark colour reaching 
from the thyroid cartilage to the seventh tracheal 
ring on each side. 
The larynx of the Marsupialia consists of a 
cricoid, thyroid, and arytenoid cartilages and 
an epiglottis. The latter is always remarkable 
for its large size, and generally for its emar- 
ginate apex. There is no muscle ing from 
the epiglottis to the tongue; its is con- 
nected in the Kangaroo by a triangular fascia 
to the body of the os hyoides and the greater 
cornua; and a small muscle passes from the 
middle part of the body of the os hyoides to 
the dorsum lingue. 
In the Phalangers the epiglottis is broad 
and short, and with a bifid apex. In the Pe- 
rameles and Phascogale the sides of the broad 
and short epiglottis are attached to the apices 
of the arytenoid cartilages, retaining thus much 
of its early condition, which will be adverted to 
in the account of the peculiarities of the mam- 
mary fcetus. 
In the Perameles lagotis I found on the base 
of the tongue in front of the epiglottis a 
small sacculus of mucous membrane, which 
communicated by a regular symmetrical cre- 
scentic aperture, situated between the body of 
the os hyoides and the thyroid cartilage, and 
continued down in front of the thyroid cartilage : 
the surface of the cavity was smooth and lubri- 
cated, and it seemed to be for the purpose of 
facilitating a hinge-like motion between the 
thyroid cartilage and the body of the os hy- 
oides. 
The thyroid cartilage is convex externally and 
protuberant in the Phalangers and Koala, but 
MARSUPIALIA. 
a 
offers no —— modification in other Mar- 
rah a e base of the arytenoid cartilage 
is broad in the antero-posterior direction, and 
the chordz vocales short and feebly developec 
The Marsupials have little or no voice: t 
Wombat emits a guttural hissing sound: th 
Dasyurus ursinus a snarling growl or whine 
the Thylacine is described as uttering a shor 
guttural cry. I have never heard a vocal m 
of any kind from the Kangaroos, Potoroos, F 
taurists, Phalangers, or Perameles. 4 
Renal system.—The kidneys present a simp 
conglobate external form in all the Marsupial 
as in fig. 134, 0, o,and in their structureand po= 
sition in the abdomen agree with the Mamma 
lian type of structure. - 
In the Macropus Parryi the kidneys at 
situated six inches above the brim of th 
pelvis, and lying in the same transverse line 
they have the same relative position in othe 
Poephaga. ¥ 
In the Koala the right kidney is higher by 
its whole length than the left. In the D 
uri macrurus and viverrinus, the right kidn 
lies half an inch higher or in advance of th 
left: in this carnivorous genus a few branch 
of the renal veins are distributed upon the su 
face of the kidney, but not in the same pre 
portion or with the beautiful arborescent di: 
poe characteristic of the kidneys of th 
ats, Suricates, and Hyena. In a Dasyuru 
macrurus weighing three pounds eight ounces 
the two kidneys weighed thirteen drachms. 
In a Phalangista vulpina, weighing five poun 
three ounces, the two kidneys weighed ; 
ten drachms. 
The substance of the kidney is divided int 
a cortical and medullary Boni the former i 
generally a thin layer. e tubuli urinifei 
terminate on a single mammilla which project 
into the commencement of the ureter in th 
Opossums, but does not extend beyond 
pelvis of the kidney in the Kangaroos. | 
the Kangaroos the medullary substance for 
several lateral abutments to the base of tl 
main mammilla. 
The supra-renal glands generally present th 
relative position ae proportions to the kidney 
represented in the Kangaroo, at fig. 13 
They are, asin most of the smaller quadre 
less flat than in man: the right body genera 
adheres to the coats of the vena cava, and t 
left to the renal vein. In the Dasyures the e: 
ternal stratum is light-coloured ; this surrounc 
a dark-coloured layer, and then there is a lig 
coloured central part, but no cavity. vy 
The ureters terminate at the back of the ne 
of a muscular and pendulous urinary blade 
(t), which only exhibits a trace of urachus | 
the middle of its anterior part in the youn 
marsupial, while in the maternal pouch, 
Male organs of generation— The testes, 
which are still abdominal at the time of b 
descend, soon after the feetus is } 
the pouch, into the external pedunculate pre- 
penial scrotum; the canal of communica- 
tion between the abdominal cavity and the tu- 
nica vaginalis is long and narrow, but always 
remains pervious, 
