432 MR. A. H. G. DORAN ON THE MORPHOLOGY 



VI. In the Bovidse the head of the malleus is not produced forwards, as in the Pigs ; 

 the articular surface is wide and shallow in the adults of the large species. The crura 

 of the incus are always long ; the body is solid, and very high in the Ox, shallower in the 

 Sheep : the stapes is quadrilateral in the larger members of this family. The foetal 

 ossicula of the great Bovidse much resemble the ear-bones of the full-grown smaller kinds- 

 The gradations of type between Ovis and Bos, and the intricate distinctions between 

 the ossicula of different genera of Antelopes, have already been discussed. 



VII. The ossicula of the Giraffe are very similar to the same in the adult Ox. 



VIII. In the Cervidse the malleus is of the type seen in the Calf, or in the adults of 

 smaller Bovidse. The processus muscularis is stout, but short in the genus Cervus ; the 

 incus has a very shallow body, with very large crura, even in Moschus, which may thus 

 at once be distinguished from Tragulus. The stapes is always triangular. 



The Ossicula of the Htraces. 



In Hyrax (PI. LX. fig. 35) the upper part of the head of the malleus is a wide, 

 smooth, spheroidal surface ; the articular area is extremely shallow, wide in both direc- 

 tions ; and there is not a trace of any groove dividing the facets. The neck is narrow and 

 rather long ; there is no lamina. The manubrium is well recurved at the tip, which is 

 slightly spatulate ; close to its root a small tubercular processus muscularis is generally 

 perceptible. The outer aspect of the whole manubrium is sharply bordered and narrow ; 

 there is a rudimentary processus brevis. 



The incus is remarkable for a peculiarity already noted by Hyrtl : the body is ex- 

 tremely small, whilst the crura are both long and divergent. That anatomist describes 

 those processes as thin ; but in both Hyrax dorsalis and H. capensis they are stout 

 and well-developed. 



The stapes is perfectly triangular, with a small head and very straight crura. The base 

 is thick and bullate towards the vestibule *. 



The ossicula of the Hyraces recalls rather those of the Equidse than their repre- 

 sentatives in any Artiodactyle or Rodent. The malleus is not unlike that of JEquus, 

 where also the processes take considerably from the size of the body of the incus ; the 

 triangular form of stapes prevails, too, among the Perissodactyla. 



The Ossicula or the Insectivora. 



In the different families that compose this Order we meet with great variations in the 

 form of the ossicula, which are sometimes of almost as low a type as their representatives 

 in the Marsupials ; in other instances they assume characters seen even in the higher 

 Primates. It is in the Insectivora that we so often find a bony canal between the crura 

 of the stapes, giving support to a small vessel, the " Steigbiigelarterie " of Hyrtl. This 

 canal has already been described as existing in the genus Lemur and in some Rodents. 

 It reaches, however, the highest degree of development in the Order now under con- 



* According to Prof. Owen, " the basse of the stapes is rarely ossified beyond the circumference." In the speci- 

 mens in the College collection a bulla exists. 



