OF THE MAMMALIAN OSSICULA AUDITUS. 497 



Plate LXIV. 



Figs. 1-6. Left ossicular 1, Bradypus tridactylus ; 2, Choloepus didactylus ; 3, Tatusia peba ; 4, Dasypvs 



sexcinctus ; 5, Priodon gigas ; 6, Tolypeutes tricinctus. 

 Fig. 7. Left malleus : Tatusia hybrida (new-born). 

 Fig. 8. Left ossieula : Manis dalmanii. 

 Fig. 9. Left incus : Manis tricuspis. 



Fig. 10. Left malleus : Manis dalmanii. Head, much enlarged, to show articular surface. 

 Fig. 11. Left ossieula, Myrmecophaga jubata. 

 Fig. 12. Left malleus and incus : Tamandua tetradactyla. 

 Figs. 13-22. Left ossieula : 13, Cyclothurus didactylus ; 14, Orycteropus capensis ; 15, Didelphys virgi- 



niana; 16, Dasyurus maugcei ; 17, Thylacinus cynocephalus ; 18, Phascogale ; 19, Myrmecobius 



fasciatus ; 20, Phalangista vulpina ; 21, Phalangista cookii ; 22, Petaurus flaviventer. 

 Fig. 23. Left malleus : Petaurus taguanoides. 

 Figs. .24-27. Left ossieula: 24, Phascolarctos fuscus ; 25, Perameles ; 26, Chceropus castanotis ; 27. 



Macropus laniger. 

 Fig. 28. Left malleus : Halmaturus Bennettii {in situ). 

 Fig. 29. Left malleus and incus : Lagorchestes. 

 Fig. 30. Left ossieula : Hypsipi'ymnus. 

 Fig. 31 . Right malleus : Macropus major. 

 Fig. 32. Left ossieula : Phascolomys vombatus. 

 Fig. 33. Right malleus : Phascolomys vombatus. 



Fig. 34. Right malleus : Phascolarctos, showing great width ; upper portion of the manubrium. 

 Fig. 35. Right malleus and incus: Echidna (Tachyglossus) hystrix, from without; shm, scale-like 



process from head of malleus, concealing body of incus; pb,pl, processus brevis and longus 



of incus. 

 Fig. 36. Left malleus and incus: Echidna, from within; hm, head of malleus; pg, processus gracilis; 



phm, process from head of malleus, blending with processus gracilis. 

 Fig. 37. Right malleus and stapes : Ornithorhynchus paradoxus. 

 Fig. 38. Left malleus : Ornithorhynchus. 

 Figs. 39-48. A series of stapedes of mammals, " columellse " of Sauropsida, displaying the gradations of 



type in the Mammalia of the occasional reappearance of the bicrurate stapes in Aves : ms 



medio-stapedial element in columella of Sauropsidan, equivalent, according to Professor Parker, 



to the processus longus of the mammalian incus. 

 Figs. 39-43. Stapes : 39, of Man ; 40, White Bear ; 41, Virginian Opossum ; 42, Great Kangaroo ; 43, 



Tasmanian " Wolf " {Thylacinus). 

 Figs. 44-48. Columella: 44, of House-Sparrow; 45, Nightingale ; 46, Golden Eagle; 47, Wandering 



Albatross {Diomedea exulans) ; 48, Nilotic Crocodile (adult). 

 N.B. The stapes of Homo, 39, is drawn on the scale maintained as the rule throughout these plates : 

 so likewise are 46, 47, and 48. The remaining stapedes are represented of the same size as fig. 39, for a 

 better comparison of their general forms. 



