MUSCULAR SYSTEM OF MAMMALIA. 21 



The sternocervicalis arises from the upper and outer angle of 

 the manubrium sterni, close to the inner (mesial) side of the 

 sternomaxillaris, by a thin tendon, which soon becomes fleshy, 

 and the slender muscle gradually contracts to be inserted into the 

 fourth cervical vertebra. 



The sternomastoideus arises from the outer angle of the manu- 

 brium sterni, by a tendon which, at one inch from its origin, 

 becomes a fleshy flat muscle ; this gradually increases in thickness 

 to a rounded form, then contracts, and forms a tendon inserted 

 into the paroccipital. 



The sternomaxillaris arises from the inner side, near the upper 

 and outer angle of the manubrium sterni, and from the manubrial 

 fascia, central of the clavicular fascia, and of the origins of the 

 sternomastoideus and sternocervicalis. Its origin is by a flat 

 short tendon : an aponeurosis passes from one tendon to that of 

 the fellow muscle. The fleshy part forms a long slender band, 

 which passes forward, and, about four inches from its origin, sends 

 off a slender fleshy strip to the ceratohyoideus. It then advances 

 as a slender round fleshy muscle, which degenerates into a sub- 

 compressed tendon about half an inch in length, opposite the 

 compressor salivaris. Resuming its fleshy structure, it forms an 

 anterior subcompressed belly, ten inches in length, and from four 

 to five lines in diameter. This gradually contracts, and terminates 

 in a slender tendon three inches long, which expands to be in- 

 serted into the outer and under part of the maxillary ramus, six 

 inches in advance of the angle of the jaw. 



To the action of the pair of muscles so inserted is mainly due 

 that characteristic movement of the head of the Great Anteater 

 when it composes itself to sleep, and draws its head downward 

 and backward between the fore-limbs, in contact with the chest. 

 The mouth is small, and susceptible of so slight an opening as 

 not to require for that action the usual modification of this part 

 of the sterno-cleido-mastoideus muscle. 



The proper muscles of the jaws consist of the temporalis, the 

 masseter, and the pterygoidei. The chief peculiarities of the 

 muscles in the present species relate to the unusual developement 

 and movements of the tongue. The mylohyoideus is of unusual 

 extent, and is divisible into different portions : two of these 

 represent the normal mylohyoideus, and extend from the sym- 

 physis mandibular backward as far as the ascending ramus of the 

 jaw. A third portion arises fleshy from the inner side of that 

 ramus, whence its fasciculi radiate toward the middle line, in a 

 somewhat twisted course, the anterior ones passing beneath the 



