ON THE MAMMALIAN OSSICULA AUDITUS. 429 



exceeds the incus of the Pigs in height as much as the incus of some other Antelopes 

 exceeds that of Sus in breadth. 



In the Harnessed Antelope (Tragelaphus scriptus) the malleus has a wide articular 

 surface and a very long, slender manubrium, which is almost straight. In Damalis luna- 

 tus, D.pygarga, and Alcelaphus bubalis (PL LXI. fig. 19), the articular surface is always 

 wide, as in Bos, but the manubrium is rather broad at the base and more curved than in 

 Tragelaphus. In all these genera the incus has a very shallow body, with very large, 

 thick, and long crura, somewhat as in the Cervidae. The only stapes in the College col- 

 lection (from A. bubalis) is triangular. 



Catoblepas gnu and G. gorgon are remarkable for the great length and slenderness of the 

 manubrium mallei, which is slightly turned up at the tip (fig. 26). The head is very 

 small, the articular surface is wide and smooth,, and the processus muscularis is mode- 

 rately developed. The stapes of G. gorgon is triangular, of C. gnu more oblong from the 

 crura being more parallel. In both the anterior crus is the thinner. 



In the Musk Ox (Ovibos moschatus) the malleus (PI. LXI. fig. 31) resembles that of 

 Bos, but the manubrium is straighter, the body of the incus (fig. 40) is not so high, and 

 the processus longus is as sharply curved as in the Sheep. As the crura of the stapes 

 diverge a little, that ossicle takes the form of an isosceles triangle with a narrow base. 



The left ossicula from an adult Anoa (figs. 32, 41) all resemble those of Bos in the 

 broad articular surface and well-curved manubrium of the malleus, the high body and 

 long crura of the incus, and the slender anterior crus of the stapes, which bone, how- 

 ever, is triangular from the divergence of the crura. The head bears a large tubercle for 

 the stapedius. 



In Camelopardalis giraffa the auditory ossicles (fig. 21) are remarkably like those of 

 the Ox, and undergo similar changes in the growth of the young animal. 



The articular surface of the malleus in an adult and a young male is still wider and 

 more plane than the Ox ; the manubrium is strongly curved. The incus is all but iden- 

 tical in form with the Ox's ; the body is very well-developed ; the stapes is almost rhom- 

 boidal ; the anterior crus is much longer than the posterior, and more slender (fig. 21). 



In the ossicula of a new-born or very young Giraffe, the articular surface of the 

 malleus is deeper, and not so wide vertically nor so plane as in the adult, the manu- 

 brium is much straighter, the incus has a far shallower body, and the stapes is almost 

 triangular. All these characters remind the observer of the changes which occur in the 

 development of Bos. 



The ossicula of the Deer are very small and light, a set from an adult Cervus (PI. LXI. 

 fig. 20) of large size being all smaller than a series from Gazella dorcas. The foetal 

 type of Bos prevails more strongly and persistently among adult Deer than even in 

 Ovis. The head of the malleus in the Red-deer is very little developed : and the articular 

 surface is deep, very saddle-shaped, and narrow vertically ; the manubrium is long and 

 slender, only slightly bowed and recurved at the tip ; the processus muscularis is a short 

 stout tubercle ; the lamina is very broad. The incus has a very shallow, ill-developed 

 body, with a long, stout, diverging posterior crus, and a short processus " longus," sharply 



SECOND SERIES. — ZOOLOGY, VOL. I. 3 M 



