Sthenurus atlas (Owen). 
On the 6th of November, 1906, I published, as the second of the 
Museum Brochures, a short account of a mutilated cranium discovered by 
Mr. James McKie Bowling, at Surprise Bay, King Island. After detailing* 
its various osteological characters, and illustrating the specimen by two 
photo, process blocks, 1 ventured to provisionally classify it as being a small 
species of Procoptodon with a bias in favour of its being “Procoptodon 
rapha" of Owen. At this time 1 was quite unable to refer to Professor 
Owen's original paper, and based my conviction of its being a Procoptodon 
upon Lvdekker's statement that the mandibular symphysis of Sthenurus is 
not ankylosed (vide Cat. Foss., Mamm., Brit. Mus., Vol. 5, Page 232), while 
that of Procoptodon is ankylosed in the adult condition (loc. cit., Page 233;. 
As the cheek teeth of our specimen were indicative of immaturity, while the 
jaws were ankvlosed, 1 simplv regarded this as an illustration of early super¬ 
ossification; but, as will he seen presently, Mr. IV Glauert has arrived at quite 
another conclusion. W hen working up a new Register in 1910, 1 recorded 
the following emendation:—“This fossil is a species of Sthenurus. and my 
former classification, based u; on the ankylosis of the mandible alone, is, I 
fear, no longer tenable." The fossil appeared in our exhibited collection as a 
species of Sthenurus, and was duly listed as such. In September, 19W ni >* 
Committee authorised the loan of this specimen to the Western Australian 
Museum, to enable Air. Glauert to make an exhaustive study of the cranium 
in comparison with his type skull of “Sthenurus occidentalis." and when 
returning the loan lie reported as follows:—**I am much obliged to your 
Trustees for the opportunity of examining the most perfect cranium of 
Sthenurus atlas in existence. Our specimen of S. occidentals is much more 
complete, and exhibits features absent from your skull. 1 think you weic 
correct in changing the name from Procoptodon to Sthenurus, as the lot met 
is merely a synonym of the latter." In the same letter Mr. Glauert gives rea¬ 
sons for a personal conviction that the lower jaws of our specimen really be¬ 
long to an older animal. In this connection, 1 have since gone over all old 
notes, and personally debated the point with Mr. Bowling as to the finding 
of the bones, and the evidence is such that a mixing—in so hard a matrix—of 
( 2 ) 
