OF THE MAMMALIAN OSSICULA AUDITUS. 391 



In the Eelid^; the malleus (PL LVIII. fig. 32), a bone of light construction, exhibits 

 the general characters already described. The head is moderately developed ; the arti- 

 cular surface is narrow vertically, but very deeply cut ; the upper facet is nearly flat, 

 the lower quite convex ; they are separated by a groove, wbich is very sharply marked 

 towards the inner limit of the articulation, but fades completely before reaching the 

 outer border. In the characters of this surface the smaller Cats may be known from the 

 Civets. The manubrium is not only narrow at the base, but its outer aspect, though 

 sharply bordered anteriorly and posteriorly, is extremely narrow throughout ; and the 

 whole process, though well recurved at the tip, is not strongly bowed, with its concavity 

 forwards. The last two points distinguish the feline malleus from that of the Dogs, 

 the Hyaena, and Froteles. The extremity is only slightly spatulate, as in most Carnivora. 

 Prom the inner side of the thin, curved neck proceeds a long sickle-shaped processus 

 muscularis, as in the Canidae and the Weasels, much more slender than in Froteles and 

 FLycena, and better developed than in Cryptoj>rocta, the Viverridap, Procyonidse, and 

 iEluridae ; in the Bears it is absent. The lamina is well developed, though never as 

 wide as in the smaller families ; even in the largest Lions and Tigers it remains papery 

 and semitransparent, not so compact as in Hyaena. 



The body of the incus (PI. LVIII. fig. 42) is deep ; its posterior crus is always well- 

 developed ; the Sylvian apophysis is small. 



The stapes (PI. LVIII. fig. 56) has straight crura, with a wide aperture between them ; 

 and the thin but broad base is more or less convex towards the vestibule. 



All the above characters are best seen in the Lion, where the lower facet of the arti- 

 cular surface of the malleus is unusually concave. In all the animals this facet lies 

 rather external to the upper, the outer extremity of the articular surface is higher 

 than the inner,, but never to the extent seen in Man and in many monkeys. In the 

 Tiger, the manubrium is rather more slender than in the Lion. In the Cat (PL LIX. 

 fig. 1) the angle at the outer aspect of the base of the manubrium projects so much as 

 to form a true "processus brevis." In the Leopard, the groove between the facets 

 of the malleus almost reaches the outer border of the articular surface, and there is a 

 distinct concavity of both facets external to the point where the groove ceases, an 

 approach to the Viverrine type. In the Cheetah {Felis jubata) the manubrium is some- 

 what shorter than in the above cats, and more distinctly spatulate at its termination. 

 The Serval has a stapes with long slender crura, much less divergent than in most 

 Carnivora. In F. lynx and F. caracal the malleus has a stouter processus gracilis, and 

 is altogether more solid than in other cats of the same size. This is not the case with 

 F. caligata, which has a very broad lamina to the malleus, as in the European Lynx. 

 These smaller Pelidae retain the characters of the articular surface of that bone as seen 

 in the Lion. 



In the HviENiD^ (PL LVIII. fig. 34) the malleus is of stouter build than in any 

 other family of the Pissipedia, excepting, perhaps, certain large Canidae ; the head is 

 greater than in the Cats, yet not large in proportion to the development of the rest 

 of the bone. The articular surface is wider than in Felis ; and the groove, well marked 

 internally, fades in the middle of the articulation; the facets it divides are flatter. 



3g2 



