L901.] MOB MUSOLBS OF THE TOTGVLATA, 661 



B thin sheet of muscle which we found in the Pig and Mouflon, 

 and which is figured by Ouvier and Laurillard in the Wild Boar 

 (I.). We are unable to homologize it with any of the facial 

 muscles of human anatomy, but we have little doubt that it is 

 present in more than the two animals in which we have recorded 

 it, and that its thinness and superficial situation have caused it to 

 escape our notice as well as that of other writers. The fibres 

 cover the whole of the side of the snout and run downward and 

 slightly forward to the upper lip. 



Levator labii mtperioris. — The nomenclature of the lip and nose- 

 muscles of Ungulates is extremely difficult, owing to the fact that 

 the veterinary writers have names of their own, while human 

 anatomists have tried to trace homologies with the muscles of 

 Man's face ; the matter is still further complicated when one 

 realizes that there is almost as much difference between the nose- 

 aud lip-muscle- of the Horse and the Pig as there is between 

 either of these animals and Man. In the Horse and Asa i h.- 

 muscle, which is usually called levator labii superioris, rises from 

 just iu front and below the orbit, and runs down to the upper lip. 

 it- tendon passing with that of the other side between the two 

 nostrils. Physiologically the muscle well deserves its name, but 

 it i- clearly not the same muscle as the levator labii superioris of 

 Man. 



In the Ox (32) the same muscle i- seen, but its origin i- much 

 lower down on the maxilla. In other members of the Bovida?, 

 such as the Mouflon Sheep (45) and the Duiker-bok (49) (see 

 text-figs. 86 and S7), this muscle ends in the nose just above the 

 nostril instead of being continued on to the upper lip. and now 

 the name of levator labii superioris becomes objectionable because 

 it i» misleading. We should like to suggest that this and the 

 other muscles which run from the maxilla to the nose should be 

 called naso-maxillary muscles, and be identified as superior, middle, 

 and inferior, but experience in this direction has shown us the 

 risk of adding to the existing confusion by giving fresh names 

 (see text-fig. 86). 



Levator labii superioris ttlceqw nasi. — This muscle is well named 

 in the Horse, and rises from above and in front of the orbit ; 

 below it divide- for the side of the nostril and angle of the mouth. 



In the Tapir (55) the muscle is extremely well developed, and 

 in the Oi (32) ii is also well-marked. In the Deer and Antelopes 

 it is suppressed, owing to the great development of the suborbital 

 glands; and in the Sheep (39) and Mouflon (45), where rudiments 

 lit' Ihis gland persist, the muscle is also absent. In the Suidie, too 

 (5, 7, 10, 11, 13, 14 i. the muscle is absent, unless it- rudiment- are 

 present as the auperficialia faciei already described. 



Dilator narii [retractor narie). — There are usually two fleshy 

 bellies rising close together from the canine fossa of the maxilla 

 below the infraorbital foramen, and ending by a number of fine 



tendon- in the -kin of the side of the QOStnl ami of the upper lip 



-7t. A- we hare already pointed out. in the Bovidsc. 



