176 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. 



DESCEIPTION OF PLATES VII. AND VIII. 



Plate VII. 

 Fig. 1. Under view of the Cranivun of Nototherium Mitchelli, Owen ( Zygo- 



matuTus trilobus, Macleay) : one-sixth natural size. 

 Fig. 2. Side view of the same : one-sixth natural size. 

 Fig. 3. Upper view of the same : one-sixth natural size. 



Fig. 4. Terminal view of the nasal region of the cranium : one-sixth natural size. 

 Fig. 5. Similar view of the cranium of the Koala (Fkascolarctus) ; one-half 



natural size. 

 [These figures, excepting fig. 5, are taken from the casts of the skull presented 

 to the Trustees of the British Museum, and received since the reading of the 

 foregoing paper. The original specimen is in the Museum of Sydney, N. S. Wales.] 



Plate VIII. 

 [The figures are reduced from specimens in the British Museum.] 



Fig. 1. Cranium of Manatus Americanus. 



Fig. 2. Skull of Phascolarctus fuscus. 



Fig. 3. Cranium of Tapirus Americanus. 



Fig. 4. Series of upper molar teeth of Tapirus, showing the greater attrition of 

 the antepenultimate molar, m i, in comparison with the tooth in ad- 

 vance, p 4. 



Fig. 5. Series of upper molar teeth of Nototherium, showing the less attrition of 

 the antepenultimate tooth in comparison with the tooth in advance. 



On a Collection of Aitstealiajs^ Fossils in the Museum of the 



Nattjeal Histoet Society at Woecestee; with Desceiption^s 



of the LowEE Jaw and Teeth of the Nototheeium ijsteeme and 



ISToTOTHEEiUM MiTCHELLi, Owen ; demonstrating the identity of the 



latter species with the Zygomatueus of Macleay. 



By Professor Owen, F.E.S., F.G.S., &c, 



(Read June 23rd, 1858.) 



[Plate IX.] 



Since the commtmication of the remarks on the photographs of the 

 fossil cranium referred by Mr. W. S. Macleay to a new genus of 

 Marsupialia, which he has called Zygomaturus, I have received, for 

 examination, through the liberahty of the Council of the Natural 

 History Society of Worcester, a series of specimens of mammalian 

 fossils from the Condamine Eiver and Darling Downs, Australia ; 

 there have also arrived at the British Museum casts of the cranium, 

 and of the upper jaw and teeth of the Zygomaturus, liberally pre- 

 sented by the Trustees of the Museum at Sydney, IN'. S. Wales, by 

 which I am able to demonstrate that this cranium belongs, as I su- 

 spected it might, to the genus Nototherium, and to that species which, 

 in my " Eeport on the Extinct Mammals of Australia," I dedicated 

 to the then Surveyor-General of Australia, Col. Sir Thomas L. 

 MitcheU*. 



The Worcester collection of fossils, contributed chiefly by Mr. 



* Nototherium Mitchelli: see p. 13 of Owen, ' On the Extinct Mammals of 

 Australia,' 8vo. 1845, p.p. 21, Plate i — vi, 4to. ; also, ' Catalogue of Fossil 

 Mammalia, Mus. Coll. of Surgeons,' p. 314, Plates iii. and iv. 4to. 1845. 



