OF THE MAMMALIAN OSSICULA AUDITUS. 399 



The neck is somewhat stout and boldly curved. The manubrium is not unlike the 

 same in Felis, but generally shorter and broader near the base; it turns up at the tip, 

 which is slightly spatulate ; but the outer aspect is rather narrow. It never forms the 

 bold curve seen in the Canidse, Hysenidse, and Protelidse. The processus muscularis is 

 a mere tubercle or almost imperceptible elevation close to the root of the manubrium. 

 The processus gracilis always diverges considerably from the neck, so that the lamina 

 is very broad, as in Procyon, whereas the same is narrow in Mustela. 



The incus (PI. LYIII. fig. 49) has a very small processus brevis, whilst the stapedial 

 crus stretches far forwards, and supports a Sylvian apophysis in the form of a disk on a 

 very narrow peduncle. The stapes (PI. LYIII. fig. 64) has a well-formed head and 

 rather slender crura. 



In the Polar Be&v (TJrstis maritimus, PI. LVIII. figs. 36, 49, & 64) all these characters 

 are well marked. The neck forms a sharp curve close to the manubrium, rather ap- 

 proaching the condition described in Cercoleptes; but it is placed lower, and does not give 

 an appearance of false length to the manubrium. This process is stout, sharply angled 

 at the base, and well recurved at the tip. The processus muscularis is represented by 

 a tubercle nearly as large as in Paradoxurus. The shortness of the processus brevis 

 of the incus, and the length and divergence of the other crus, are very marked ; the 

 latter bends, forming a prominent knuckle, before contracting to give attachment to the 

 peduncle of the Sylvian apophysis. There is a rather wide aperture between the crura of 

 the stapes ; the base is broad and plane. 



In the Spectacled Bear ( TJrsus ornatus, PI. LIX. fig. 17) hardly a trace of the processus 

 muscularis can be found on the malleus ; the manubrium is rather long and slender, little 

 recurved at the tip, and not sharply angled at the base. In an incus in the College col- 

 lection there is a slight tubercular projection close to the extremity of the processus longus, 

 just above the Sylvian apophysis. The crura of the stapes are rather thick, with a 

 small aperture between them. 



The malleus of the Himalayan Bear ( TJ. tibetanus) is more like that of TJ. maritimus, 

 especially in the manubrium, which is not very long, and is broad at the root, sharply 

 angular at the base and well recurved at the tip ; but there is hardly a trace of processus 

 muscularis. The anterior crus of the stapes is distinctly curved. 



In the Sloth Bear {Melursus labiatus) the head of the malleus is less developed than in 

 an TJrsus of the same size. The manubrium is less stout and recurved than in the large 

 species of the typical genus, but is as angular at the base. There is no trace of any 

 processus muscularis ; the lamina is very wide, and bounded in front by a prolongation 

 of the head, which joins the processus gracilis, a condition seen less plainly in other Car- 

 nivora, but constant in some other mammals. 



The Ossictjla of the Pinnipedia. 



The ossicula of the majority of the Seals and their allies are not only very large but 

 also - well-marked and readily distinguishable in the different genera or even species. 

 The ossicles of the Otariidse differ from those of the other families in their absolutely 



3h2 



