OF THE MAMMALIAN OSSICULA AUDITUS. 439 



broad process, ankylosed to the tympanic ring in the adult. This process is broadest 

 towards its extremity, which is well rounded; it is much flattened laterally; and as 

 it stands at right angles to the plane of the lamina, it presents a very characteristic 

 appearance. Close to its root, at about the point of junction of the processus gracilis 

 with the process from the head, it is perforated for the passage of the chorda tympani 

 nerve. 



The malleus of JE. dealbatus is very similar to that of the common British species. 

 The prolongation of its processus gracilis is even wider and longer ; but the lamina is not 

 quite as broad. 



That the rod-like projection from the inner side of the neck of the Hedgehog's mal- 

 leus is the true processus muscularis there can be no doubt, as the tendon of the 

 tensor tympani muscle will be found attached to it in the recent skull ; nor, from the 

 nature and position of the prominence nearer to the malleus, can it very well be other- 

 wise than the homologue of the orbicular apophysis of Sorex, which is not utilized in 

 this animal for the attachment of the muscle, a distinct processus muscularis existing 

 as well. It seems extraordinary that the malleus of the common Hedgehog, broken in 

 half, should ever have been taken for two ossicles ; yet Hyrtl has corrected that erro- 

 neous opinion enunciated by a previous observer. Such a mistake could scarcely have 

 been made if the homologies of the fragments of that or any other ossicle had been care- 

 fully made out. 



The incus of the Hedgehog lies almost vertically above the malleus in the recent 

 skeleton. Its body is wide and shallow ; the processus brevis is very short, but stout, 

 and pointed. The stapedial crus is long, stout, rounded, and very divergent from the 

 body; near its root, to the inner side, it bears a small tubercle, and at its extremity a 

 well-developed Sylvian apophysis on a narrow pedicle. In their general characters the 

 incudes of the Hedgehog and of most of the musteline and arctoid Carnivora agree ; but 

 the remaining ossicles are totally dissimilar. 



The stapes of the Hedgehog has a very- small head, with a small tubercle for the 

 stapedius-tendon on its posterior aspect. Both crura are very slender, grooved towards 

 the aperture, and much curved, so as to be furthest apart midway between the head and 

 the base. The posterior is often the straightest. A large vessel passes through the wide 

 aperture in the recent skull, not enclosed in a bony canal. The base is narrow and 

 almost plane towards the vestibule. 



In the Bulau (G-ymmira JRafflesii, PL LXII. fig. 14) the head of the malleus is better 

 developed than in Erinaceus, but still small ; the articular surface is of similar character . 

 The neck is much shorter and more sharply curved. Prom its inner aspect, near the 

 handle, there projects a very conspicuous slightly curved processus muscularis ; and 

 closer behind the manubrium is a prominent, but sessile, convex process, eviden tly the 

 homologue of the orbicular process in the Shrew. The presence of both these projections, 

 equally well developed in this animal, is of great value in considering, by comparison, 

 the homologues of the single process in Myogale and in other Insectivora. The manu- 

 brium is much laterally compressed, but not very broad at the root ; the site of the pro- 

 cessus brevis is rounded off, and not prominent. The lamina is much narrower than in 



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