THE SHOULDER-GIRDLE IN DASYURUS AND PRRAMELES. 419 
On the Early Condition of the Shoulder-Girdle in the Polypro- 
todont Marsupials Dasyurus and Perameles. By Rovert 
Broom, M.D., C.M., B.Sc. (Communicated by Prof. G. B. 
Howes, F.R.S., Sec. L.S.) 
[Read Ist May, 1902.] 
(Puate 41.) 
Iv 1897 I discovered that the Common Phalanger (Trichosurus 
vulpecula) has at birth a well-developed coracoid, which is firmly 
attached to the sternum, and I recorded the fact at the time in 
a short note in the ‘ Journal of Anatomy and Physiology’ (1). 
In 1899, Sir William Turner communicated to the Royal 
Society of Edinburgh for me a paper (2) dealing at length with 
the development of the shoulder-girdle in Trichosurus vulpecula, 
and containing some observations on the early condition of the 
girdle in Pseudochirus and Petrogale. Since then, through the 
kindness of my friends Prof. J. T. Wilson and Mr. J. P. Hill, 
of Sydney, I have been enabled to study one or two stages 
in the early development of the shoulder-girdle of two of the 
Polyprotodont genera—Dasyurus and Perameles. 
DasSYURUS VIVERRINUS (Harly Stage). (Pl. 41. figs. 1 & 2.) 
The younger of the two stages of Native Cat which I have 
examined measures in the curved condition 8 mm. greatest 
length, and had a head-length of 4mm. At birth, according to 
Hill (3), the new-born young measures, when preserved in spirit, 
5°5 mm. G.L. and 2°3 mm. H.L., so that the specimen examined 
would probably be 4 or 5 days old. In its general skeletal 
development it is slightly more advanced than is the new-born 
Trichosurus. In the head the following bones can be detected :— 
premaxillary, maxillary, lachrymal, jugal, squamosal, palatine, 
pterygoid, and mandible. In the post-cranial skeleton ossifica- 
tion has commenced in the scapula and in the first two ribs, 
while the clavicle is well ossified. 
Asin the Diprotodont marsupials which have been examined 
the early mammary feetal Dasyurus has a complete shoulder- 
girdle, the well-developed coracoids articulating with the steruum 
LINN. JOURN.—ZOOLOGY, VOL. XXVIII. 32 
