Lect. II.] ANCESTORS OF THE MAMMALIA. 47 



much as, or more than, the skull of the Ornitho- 

 rhynchus differs from that of a Man. 



We may suppose the ancestors of the original teatless 

 mammals (Prototheria) to have been something like, and 

 not much higher than, the larva of the nailed Toad, and 

 that these underwent an amount of transformation, 

 during an active out-of-door life, equal to that under- 

 gone by the existing type. Afterwards, by little and 

 little, such Prototheria may have improved themselves 

 into higher and still higher types ; they have had plenty 

 of time for such changes. 



addendujm to lectuee it. 



Bibliography: Eeferences to Works and Papers treating 

 OF the Ornithorliynclius and Echidna. 



Armit, Captain William E., F.L.S., "]S"otes on the Presence of 



Tachyglossus and Ornithorliynclius in JSTorthern and IN'orth 



Eastern Queensland," Proceedings of the Linnean Society, 



Zoology, vol. xiv., 1879, pp. 411-413. 

 Bennett, Dr George, F.L.S., F.Z.S., &c., Gatherinrjs of a Naturalist 



in Australia. London : John Van Voorst. 1860. 

 Flower, Prof. W. H., LL.I)., F.E.S., An Introduction to the 



Osteolofjy of tlie Mammalia. London: Macmillan & Co. 1876. 

 Article " Mammalia " in the Encyclo^ocedia Britannica, 9th 



edit., vol. XV., pp. 377-378. 

 Huxley, Prof. T. H., LL.D., Pres. E.S., A Mamial of the Anatomy 



of the Vertehrated Animals, pp. 319-323. London: J. & A. 



ChnrchiU. 1871. 



