1903.] THE MUSCLES OF THE UNGULATA. 267 



believe that these two muscles are always present in Ungulates, 

 and that the line of separation can be determined, if carefully 

 looked for, by the branch from the superior gluteal nerve to the 

 tensor fascia3 femoris passing through it. The origin is from the 

 ventral part of the gluteal surface of the ilium near that portion 

 of the bone usually described by veterinary anatomists as the 

 neck, while its insertion is into the front and outer side of the 

 great trochanter. In the Horse, Lesbres (V.) says that the ento- 

 and meso-glutei can only be distinguished from one another at 

 their insertions. The nerve-supply seems always to be the 

 superior gluteal. 



Gluteus ventralis {Gluteus quartus ; Scansorius). — This muscle, 

 when it is distinct, as it generally is in the families of Camelidse, 

 Giraffidje, and Bovidse, rises from the ventral border of the ilium 

 and is concealed by the overlapping entogluteus, and is inserted 

 into the anterior surface of the great trochanter. In Ungulates 

 belonging to other families than those just mentioned, it is often 

 difficult to separate the muscle from the entogluteus unless the 

 nerve to the tensor fasciae femoris is looked for. The nerve- supply 

 is the superior gluteal. 



Gluteus jyrofifndiis {Gluteus quintus ; Hio-capsuXaris). — It is 

 quite certain that this is not a constant and well-defined muscle 

 in Ungulates, though it is occasionally found. Lesbres (V.) 

 describes the " abductor trochitereen " in the Horse as very 

 distinct, and says that it lies over the superior surface of the 

 capsule of the hip, rises from the supracotyloid crest, and is in- 

 serted into the anterior part of the internal surface of the great 

 trochanter which is known to veterinary anatomists as the con- 

 vexity of the trochanter. He regards it as the sei'ial homologue 

 of the infraspinatus secundus (see Part I. of this paper, P. Z. S. 

 1901, vol. ii. p. 687), but it answers very well to our idea of the 

 gluteus profundus. In addition to this, he describes another muscle 

 in the Horse, rising from the ilium close to the origin of the rectus 

 and inserted into the anterior surface of the femur close to the 

 head ; this he considers is the homologue of the ilio-capsularis of 

 the Carnivora. For practical purposes it does not seem to us that 

 these two muscles require separate names ; they are probably two 

 slips of the deepest delamination of the gluteal mass lying in 

 contact with the capsule of the hip. In the Harnessed Antelope 

 (55) we found a gluteus profundus, and Kinberg (X.) describes it 

 in the Chevrotain under the name of M. tenuis femoris. In the 

 other Ungulates the muscle is not as a rule delaminated from the 

 entogluteal sheet. The nerve-supply in the Harnessed Antelope 

 is from the sacral plexus just below the origin of the superior 

 gluteal nei've. 



Pyriformis. — We have already stated that the mesogluteus is 

 usually fused more or less completely with the pyriformis, but in 

 some cases, e. g. the Duiker-bok (54) and Harnessed Antelope (55), 

 the entogluteus is more closely blended with it than is the meso- 

 gluteus ; it must, however, be remembered that in the Ungulates 



