XIX. Pelvic Characters of Thylacoleo carnifex. 
By Professor Owen, C.B., F.P.S., &c. 
Received April 13,—Read April 26, 1883. 
[Plate 46.] 
Since the communication of the 1st February, 1883, “ On the Affinities of Thylacoleo f 
I have received, through the favour of the Trustees of the Museum of Natural 
History, Sydney, and the care of the accomplished keeper, E. P Pams ay, Esq., 
F.L.S., a second consignment of the palaeontological results of his exploration of the 
Breccia Caverns of Wellington Valley, New South Wales. 
Besides additional confirmation of the dental, mandibular, antibrachial, ungual, 
and other osteal characters of Thylacoleo, these accessory specimens' afford further 
evidence of the carnivorous modifications of parts of the skeleton. Of these a 
well-marked one is yielded by the pelvis (Plate 46, fig. 1). 
I may premise that this part in Fells and Macropus shows the following differ¬ 
ences :— 
In Macropus major (Plate 46, fig. 2) the ilium, i, extends above, or anterior to, 
the acetabulum, a, into an elongate body of a triedral form : the two outer facets are 
deeply hollowed transversely, are separated from each other by a sharp well-produced 
ridge, and each is divided from the flattened and roughened mesial, or sacral, third 
surface by similar ridge-like productions bounding the respective margins of the outer 
non-articular surfaces. In Felis (Plate 46, fig. 3) the superacetabular body of the 
ilium, i, is a relatively broader plate of bone with the slightly concave outer surface 
undivided. The ilium, in Macropus, bends outward to its free tuberous end and 
contracts thereto. In Felis it slightly expands to the ridge-shaped free border. In 
Macropus the contour of the acetabular margin approaches a triangular figure, the 
truncate apex being forward or next the ilium ; the basal part of the margin is cleft 
above the canal or groove leading from the ischium, s, to the bottom of the articular 
cavity, a. In Felis the contour of the acetabulum, a, is sub-circular ; the iliac border 
is not produced into an angle. The synovial glandular pit is broader and shallower, 
and the mesial boundary of the canal leading thereto is not produced ; the lateral 
boundary alone arches over part of that canal. 
A marked difference between Macropus and Felis is the relative length and 
slenderness of the ischium, s, as it recedes from the acetabular region to the terminal 
4 N 2 
