OF THE MAMMALIAN OSSICULA AUDITUS. 443 



It differs, comparing it with the other Insectivora, very completely from the Shrews' 

 and Hedgehogs' in the smallness of the lamina and general form, and as widely from 

 that of the Tupaiidse in possessing a constricted neck and in other respects ; but it cer- 

 tainly has points of resemblance to the malleus of Itfiyncliocyon and Macroscelides, the 

 main distinctions being the form of the articular surface and the character of the lamina 

 and processus gracilis, though the latter feature is not very different in this animal from 

 that of the Elephant-shrew, except that the processus gracilis is more slender. 



The incus is very high and narrow, especially over the short crus ; in this respect it 

 exceeds the Tupaia incus and approaches that of Mycetes and Galago, though it does 

 not project over the processus longus as in the latter. The processus brevis is very short, 

 and curved backwards. The stapedial crus is stout, not very long, and bears a well- 

 developed very elliptical Sylvian apophysis on a narrow pedicle ; it does not diverge from 

 the body so much as in Tupaia ; but the incus altogether resembles that of the latter 

 animal more than that of any other insectivorous mammal. 



The stapes of a young Galeopitliecus has an ill-developed head, with slender bowed 

 crura, and a large aperture not occupied by a bony canal in the recent cranium. The 

 base is broad and very convex ; it projects far beyond both crura. In a pair from an 

 adult skull in the collection the aperture is filled by a thin lamina. 



In most respects both incus and stapes of this animal more resemble those of the 

 Macroscelidse and Tupaias than of the Shrews, Moles, and Hedgehogs. They are not 

 strongly allied to the same ossicles in any definite group of the Primates, though strik- 

 ingly like them in one or two characters above given. Hyrtl considers that the incus of 

 Galeopitliecus bears a larger Sylvian apophysis than in any other animal ; but I find it 

 larger in Myogale, Rhinoceros, Ovibos, and several other mammals. 



The above researches on the ossicula of the Insectivora lead to the following con- 

 clusions : — 



I. These bones all offer great variations in the different families of this Order ; and 

 there is no constant positive character to be foundin any of the three ossicula. The 

 stapes is never Sauropsidan or columelliform, as in Ifanis and the Marsupials ; but the 

 very frequent wideness of its intercrural aperture is perhaps not so much a sign of high 

 type, as an accidental feature in relation to a bony canal passing through it, or, at 

 least, on account of a large vessel, unsupported by such a canal, running between 

 the crura *. 



II. QJirysochloris has the most specialized ossicula in this Order. The extraordinary 

 malleus appears as if rather modified from the highest or anthropoid type than from the 

 more central laminated form of the ossicle. The almost equally peculiar incus, in the 

 development of its body and short crus, must be considered as of rather high type than 

 otherwise ; and the stapes is quite the reverse of Sauropsidan in all its characters. 



III. The ossicula of Galeopithecus are very generalized in character. The malleus 

 has several characters seen in the highest Quadrumana and in some Lemurs, most of 

 which, however, are reproduced in certain mammals as low as the Edentata. The incus 



* More will be said, however, on this topic in the description of the stapes in the insectivorous Bats. 



