128 Prof. Owen on the Fossil Mammals of Australia. [Jan. 23, 



spectrum except that under observation. The words in my book written 

 at the time are, " narrow slit found to be best at focus of little telescope 

 with positive eyepiece." In the note the second slit was stated to have 

 been placed before the object-glass of the little telescope. Such an ar- 

 rangement was tried in connexion with some other experiments in pro- 

 gress at the time. The plan of limiting the field of view to the part of 

 the spectrum corresponding to the refrangibility of the light of the pro- 

 minence, as well as the employment of a ruby glass, is of value when the 

 air is not favourable, or when a spectroscope of small dispersive power is 

 used. 



III. " On the Fossil Mammals of Australia. — Part VIII. Family 

 Macropodidae : Genera Macropus, Osphranter, Phascolagus, 

 Sthenurus, and Protemnodon." By Professor Owen, F.R.S. 

 &c. Received November 11, 1872. 



(Abstract.) 



In the present Part of the series of papers on the Fossil Mammals of 

 Australia, the author enters upon the description and determination of the 

 fossils referable to the family of Kangaroos (Macropodidae), restricting, 

 however, the latter term to the species in which the molar teeth have 

 two transverse ridges for the chief character of their grinding-surface, 

 and excluding the Potoroos (Hypsiprymnida3), in which the working- 

 surface of the molars is formed by four tubercles in two transverse pairs. 



The large extinct species of Kangaroo indicated under the names 

 Macropus Titan, M.Atlas, and M. AnaJc in former publications ('Mitchell's 

 Three Expeditions into the Interior of Eastern Australia,' 2 vols. 8vo, 

 1838, Palaeontological Appendix, vol. ii. p. 59, pis. 24-32 ; also 1 Pro- 

 ceedings of the Geological Society of London,' vol. xv. p. 183, 1858) 

 here receive further elucidation of their specific distinction from any 

 known living Kangaroos and of the grounds (according to the value 

 assigned thereto by present zoologists) for referring two of these (M. 

 Atlas and M. AnaTc) to distinct subgenera of Macropodidae. 



As the extinct Kangaroos which the present paper defines are chiefly 

 represented by fossil jaws and -teeth, some remarks on the dentition of 

 existing Kangaroos, with requisite illustrations, are premised, and the 

 parts of the complex molars are defined. 



The author then enters on the elucidation, aided by the facts pre- 

 mised, of Macropus Titan, M. affinis, Osphranter Cooperi, 0. Gouldii, 

 Phascolagus alius, Sthenurus Atlas, S. Brehus, Protemnodon AnaTc, P. Og, 

 P. Mimas, and P. Roechus. 



The maxillary, mandibular, and dental characters of these extinct 

 species are illustrated by the subjects of eight Plates. 



