100.— Magnified Hind-foot of Female Ornithorhynchus. 



103.— Portion of integument from the abdomen of Ornithorhynchus. 



109.— Jaw of Thylacotherium. 



lOV.-Smaller specimen of young Ornithorhynchus. 





Front view of mandibles of the above. 



105. — Mammary gland of Ornithorhynchus, reduced 

 below the natural size. 



110. — Jaw of Phascolotherium. 



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