416 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Apr. 13, 
“Besides a large number of Wombats (Phascolomys) the exist- 
ence of very Wombat-like Kangaroos, or rather Wallabies (Halma- 
turt), is proved by fossil remains of these animals. In fact the whole 
tribe was different from those of the present day, on account of the 
shortness of their extremities ; the skull and lower jaw also differed 
considerably ; and in the catalogue which I am preparing of these 
remains I have divided the Kangaroos into three distinct groups :— 
“1. Macropuswith dentition as the present Kangaroos, whereof 
Macropus major is the type. Premolar soon lost. 
«<2. Halmaturus, represented by the smaller Kangaroos, known 
as “ Wallabies.” Head rather shorter than in the true Kangaroos. 
Premolar permanent. 
«« 3. This group comprises all the gigantic species which have been 
referred to Macropus, but which in reality are gigantic Halmaturi, 
with very strongly developed premolars, resembling those of the 
genus Bettongia. But as there are two very distinct kinds of pre— 
molars developed, I have subdivided the Halmaturi again :— 
‘<q. Into such as have long, narrow, and compressed premolars, 
moderately elongate heads, and the rami of the lower jaw 
but slightly anchylosed; and 
««6. Into the Wombat-like Wallabies, with short heads, strongly 
anchylosed lower jaws (immovable jaws, in fact), inci- 
sors without cutting-edge. (The present Kangaroos and 
Wallabies have the rami only slightly anchylosed, and use 
the teeth like scissor-blades for cutting the grass.) The 
premolar tooth in this group is very compact, rounded, 
molar-like, and approaches in shape the same tooth in 
Diprotodon or Nototherium. 
Discussron. 
Prof. Owen remarked upon the importance of the researches made 
by Dr. Krefft and Prof. Thomson in the caves of Wellington Valley. 
No traces of man had been found. The numerous remains of 
Mammals, especially the Herbivorous species, had doubtless been 
carried into the caves by Thylacoleo. 
Prof. Busk inquired on what grounds Prof. Owen decided that 
the teeth of T’hylacoleo, of which casts were exhibited, were Carni- 
yorous. 
Prof. Owen indicated the remarkable compression of the tooth and 
the absence of the spatulate form proper to the Kangaroos, also its 
association with a large ‘“carnassial” and small ‘“ tubercular” 
tooth, as characteristic of Thylacoleo and indicative of carnivorous 
habits. 
Mr. W. Bory Dawxtns stated that Thylacoleo was most closely 
allied to Plagiaulax, which was: probably a true Herbivore. He 
indicated the importance of the question, as, if Thylacoleo were a 
Carnivore, Plagiaulax would be one also. 
Prof. OwEn remarked that Plagiaulax was also a Carnivore. The 
premolars resembled the small tubercular molars of the Hyenas, 
