112 



head and tongue of this animal. This author gives three 

 figures of the tongue, and the lingual muscles, but does 

 not make mention of other important muscles of the 

 head, as those of the jaw, the Masseter, the Pterygoid, 

 Temporal and the Digastric. 



From the similarity in function of the tongue, in the 

 Ant Eater and Tachyglossa, it would be a cause of won- 

 der if the myology of the head of the Ant Eater by 

 Owen did not prove of the greatest value. Although the 

 difference in systematic position between these two animals 

 is great, the muscles of the tongue, at least, are in many 

 respects quite alike. 



In the valuable paper on the Myology of the Echidna 

 Hystrix by St. George Mivart (Trans. Linn. Soc, 1866), 

 the muscles of the head and neck were only in part de- 

 scribed. The specimen, from which the dissection was 

 made, had its head destroyed in a trap, and on this ac- 

 count he failed to make out the myology of these parts. 



From the character of the mouth and face of Tachy- 

 glossa, we should expect that the muscles of these parts 

 of the head would be wanting or very slightly developed. 

 I have been unable to discover any trace of the different 

 facial muscles. Orbicularis Oris, Depressor Angulis Oris, 

 Zygomaticus Major and Minor. In the tough skin, which 

 covers most of the bill, in advance of the orbital foramen, 

 there are muscular fibers, which may represent these, and 

 other facial muscles. To determine their homologies, 

 however, would be a very difficult task. 



The muscles of the jaw are the Temporalis, the Masse- 

 ter, Pterygoideus Exteruus, and Pterj^goideus Internus. 

 To these may be added a Digastricus, Avhich, like the 

 same muscle in many other forms, passes directly from 

 its origin to its insertion, without passing under the slip 

 at the hyoid bone. 



