MUSCLES OF THE HEAD. 229 



4. A lachrymalis, tkicker and more developed than in the Horse. Its most anterior 

 fibres glide beneath the zygomaticus, and are lost on the alveolo-lahialis surface : the 

 most posterior pass over the aponeurotic tendon of the zygomatico-labialis, and are 

 confounded with those of the cutioularis. Above, it joins the orbicularis of the eyelids 

 in a still more intimate manner than in the Horse ; so that it is almost impossible to 

 distinguish the limits of the two muscles (fig. 112, 4). 



5. A supernaso-labialis continued, above, with the inferior border of the frontal or 

 fronto-cuticularis muscle; and divided, inferiorly, into two branches, which comprise 

 between them the supermaxillo-labialis and the pyramidalis-nasalis. These two 

 branches, however, are not disposed as in Solipeds, the anterior covering the preceding 

 muscles, and the posterior, of but little importance, passing beneath them to lose itself 

 in the substance of the upper lip (fig. 112, 3). 



6. A supermaxillo-labiaUs, which gains the middle of the muzzle by passing along 

 the inner side of the nostrils (fig. 112, 1). 



7. Two additional supermaxillo-labiaUs muscles, considered as accessories to the 

 first, and which originate with it. Each terminates by a ramifying tendon that passes 

 under the nostril to mix in the tissue of the upper lip (fig. 112, l',l'). 



8. A pyramidalis or great super maxillo-nasalis, situated between the supermaxillo- 

 labialis and its two accessory muscles, and deriving its origin, in common with these 

 three muscles, in front of the maxillary spine (fig. 112, 2). 



9. A maxillo-lahialis, confounded with the alveolo-labialis, and having no temainal 

 tendon. 



10. A mento-lahialis, attached to the body of the inferior maxillary bone, as in the 

 Horse, by two middle posterior muscles. Ko anterior middle muscle has been found by 

 us; and it is certain that there is no naso-transversalis or stnall supermaxiUo-nasalis 

 present. 



In the Sheep, the supernaso-labialis does not exist ; apart from this peculiarity, 

 there is no difterence between the facial muscles of this animal and the Ox. 



Pig. — This animal has neither the lachrymalis, supernaso-labialis, or naso-transver- 

 salis muscles. The small supermaxillo-nasalis is present ; it is short, very thick, and 

 situated near the margin of the nostrils. The supermaxillo-labialis and the great 

 supermaxillo-nasalis are replaced by three fleshy bodies, nearly parallel, lying on the 

 side of the face. The superior originates in the lachrymal fossa, and terminates by a 

 tendon in the middle of the snout. The inferior, with the middle, leaves the imprints 

 in front of the zygomatic ridge, and is continued at its inferior extremity by a tendon 

 divided into several fibrill«, which pass below the nostril to be united to the tendon of 

 the superior portion : this is done in such a manner that the external opening of the 

 nose is encircled on the inner side by a kind of fibrous cravat which, when these two 

 muscles contract, carries this opening outwards. It will also be understood that the 

 superior fleshy body, acting alone, ought to elevate the snout, while the inferior 

 depresses it in drawing it to one side. With regard to the intermediate fleshy mass, it 

 is the representative of the pyramidalis of the Ox, and terminates in a great quantity of 

 tendinous fibrillse at the internal ala of the nose. 



Caenivoka. — In the Dog and Cat the following peculiarities are found : — 



The lahialis (or orbicularis) is quite rudimentary. 



The buccinator is very thin and formed of only one muscular plane. 



The zygomatico-iabialis is continued, superiorly, with the zygomato-auricuralis. 



The supernaso-labialis represents a wide, undivided, muscular expansion, united 

 superiorly to the caticularis of the forehead, and terminating inferiorly on the upper 



lip- 



The supermaxillo-labialis and the supermaxillo-nasalis magnus constitute a single 

 fleshy body formed of several parallel fasciculi, which take their origin above the supra- 

 orbital foramen, and terminate together at the external wing of the nose and in the 

 upper lip. 



There is no supermaxillo-nasalis parvus, or naso-transversalis. 



The middle anterior {depressor alss nasi) is perfectly developed. 



The mento-labialis and its suspensory muscle, the middle posterior, are scarcely 

 apparent. 



B. Masseteric or Temporo-maxillary Region. 



In Ruminants, the masseler and temporal are not so large as in Solipeds. In the 



Carnivora, however, they offer a remarkable development. The origin of the ptery- 



goideus internus in Ruminants is nearer the middle line than in tl)e Horse. Its obliquity 



si also greater, and the movements of diduotion it gives the lower jaw are more 



18 



