ORGAN OF HEAEING IN MAMMALIA. t>35 



and wider opening than in the badger : the incus is relatively 

 small. In the wolverine (Gulo) the malleus is perforated near 

 the orio-in of the process ; repeating a character presented in some 

 birds by its cartilaginous homologue. In the otter (Lutra 

 vulgaris} the malleus, fig. 176, B, is similarly perforated; the 

 stapes is small, but adheres to the musteline type of the bone 

 and is more widely open than in Seals. In the civets the stapes 

 is triangular, its base oval, the branches thick and grooved on the 



O ' C5 



inner side : the crura of the incus are short and very divergent. 

 In Canis the stapes, ib. D, is subelongate, with the apex small, 

 the base oval : the intercrural space is large. The handle of the 

 malleus is grooved lengthwise. The stapes of the hyrena has a 

 slightly convex and longish oval base ; the crura of the incus are 

 short : the malleus is rather curved, with a short subcompressed 

 handle. The ear-conch is large and long, without any fold of 

 the external border : the tympanic is less inflated than in Feiis. 

 The cochlea is longer and more prominent in the dog than in 

 the cat. In this type-genus of Carnivora the acoustic capsule 

 and labyrinth are small, especially in the large species ; but the 

 tympanic cavity is expanded in all felines into a notable ' bulla ' 

 at the base of the skull, formed chiefly by the tympanic, which, 

 after framing the drum-membrane, forms an oval external orifice, 

 deeply seated in the narrow space between the mastoid and 

 zygoma. The stapes is a longish triangle, widely open, with 

 the apex truncate and the base oblong, fig. 176, E, Tiger; it is 

 shorter in the small Felines. The crura of the incus are short 

 and subequal; the body of the malleus is broad and long; its 

 handle of moderate length, and, in some, terminally expanded. 

 The conch is short, usually rounded, broad and widely open ; 

 relatively largest in the smaller species ; and distinguished in the 

 lynxes by the apical tuft of long hairs. 



The otosteals in Quadrumana, fig. 177, quickly approximate to 

 the characters of those in Man, ib., Homo : the stapes in Chiromys 

 has a shorter and broader summit ; its base is firmly wedged into 

 the foramen ovale. With the other otosteals it is proportionally 

 larger than in true lemurs, bearing relation to the great develop- 

 ment of the outer ears. These are large in all Lemuridce : the 

 tragus and antitragus are well marked in Stenops, but instead of 

 anthelix there are two prominent and subparallel plates. The 

 vestibule is shorter, and the cochlea closer to the semicircular 

 canals in the Aye-aye than in Man. In the Lemuridce the com- 

 mencement of the cochlea is wide, and its axis is parallel with a 

 line drawn from the fore end of the ampulla of the upper semi- 



