1865.] DR. J. MURIE ON THE SPECIES OF PHASCOLOMYS. 843 
Our skull is apparently from a younger animal, as the sagital and 
lambdoidal sutures are not obliterated as in the College specimen, 
which latter has also the supraoccipital crests and the postorbital 
angles more prominent. The frontal bones anteriorly, as well as the 
nasals at the median suture, in our specimen are very flat, whereas 
in the typical skull they are convex and considerably raised. In 
this last cranium the frontal bones in the median line extend with a 
thin narrow wedge-shaped projection forward for half an inch between 
the nasals; in our specimen the two nasal bones posteriorly form 
nearly a straight line across. The posterior palatine foramina are 
larger in our younger skull, and have between them a more slender 
columella of bone. 
Both skulls have the foramgn magnum of an oval outline; in this 
respect they materially differ from P. wombat and the type of P. pla- 
tyrhinus, which have it of a trefoil figure, as Owen* has observed. 
While studying the matter from a different point of view, by 
reason of the P. lasiorhinus taking the place of Gould’s P. latifrons, 
and upon comparing the size of several adult crania of P. wombat, 
I was struck with the great size assigned by Mr. Waterhouse +, in 
his volume already mentioned, to two skulls, namely that of Owen’s 
P. latifrons and the common P. wombat. The latter, which he con- 
sidered typical, was one in the British Museum collection, and, as 
he believed, belonged to an aged individual. 
Upon consideration, I concluded he must have had before him, and 
taken his admeasurements from, a specimen of P. platyrhinus with- 
out being aware, or at least believing, that this species differed from 
P. wombat. 
On examination of the very same skull from which his measure- 
ments were taken, proved by the exactness of its dimensions, and by 
the partial obliteration of the frontal and nasal sutures as stated by 
him to exist in the specimen, I found, to my surprise, I had been 
forestalled, while supported in opinion, as already Professor Owen, 
most possibly without being aware of this being Mr. Waterhouse’s 
type of P. wombat, had relabelled the skull in question P. platy- 
rhinus. This fact was certified by Mr. Gerrard’s showing me the Pro- 
fessor’s own handwriting on the ticket attached to the specimen. 
My attention in this way was called to think upon what might be 
considered the average or comparative limits of the size of the crania 
of the three species P. wombat, P. latifrons, and P. platyrhinus. 
The following table is the result of a series of measurements of 
skulls, chiefly those in the British Museum and College of Surgeons. 
In the first column of the table are shown the proportions of the 
typical skull of P. latifrons, Owen ; alongside of which are the corre- 
sponding dimensions of this second cranium, belonging to the same 
species: the agreement in their several proportions is very close. 
Then follow the comparative measurements of a series of crania of 
what I take for the true P. wombat; these are intended to illustrate 
the skull at different ages in this species. 
* “On the Osteology of the Marsupialia,” Trans. Zool. Soe. vol. ii. p. 383. 
tT Nat. Hist. Mamm. vol. i. p. 251, 
