BY CHARLES W. DE VIS, B.A. 301 



observation. The listening attitude assumed by the pedestrian 

 reptile, if the phrase may be excused, was so real, or at least so 

 realistic, that it at once occurred to me that one function of the 

 hood might be that of conducting sound to the tympanum, an 

 office apparently aided by the channels formed by its converging 

 folds, and that if it were so it might be furnished with special 

 muscles. After this point had been investigated it was a facilis 

 descensus to the nether extremities, where nature might be asked 

 if she had made any peculiar muscular provision for erect carriage : 

 and when this question had been put so few of the creatures 

 muscles remained intact, that it seemed well to examine the rest 

 and render an account of the whole myology of a lizard, which is 

 really inferior to few in interest. I do not propose to lengthen 

 the following descriptions with references to the muscles of 

 whatever lizards may have been previously examined, but to form 

 them as tersely as possible. At some future time an opportunity 

 may be taken of comparing the myology of some other of our 

 Australian lacertians, not only with that of the subject of the 

 present observations, but with that of all the extraneous lizards 

 which have been monographed or otherwise noticed. 



Muscles of the under surface of the head. 



Mylohyoid (Plate xiv., fig. 1 — m. h.) — At its commencement 

 very near the symphysis menti it is thick and attached to the lower 

 edge of the mandible, its fibres passing transversely from each side 

 to a median raphe ; as it recedes from the symphysis it becomes 

 gradually thinner, its insertion rises higher on the inner surface of 

 the jaw, and the course of its fibres is more and more oblique till it 

 merges into the 



Platysma myoides (fig. 1 — p.m.) which sends attenuated fibres 

 and slips to the gular region of the hood, and is lost dorsad in the 

 fascia covering the trapezius, but acquires thickness over the 

 sternum and cervix. 



Thyromandibularis (fig. 1 — t. m.) — Two distinct muscles may 

 bear this name, an externus and an internus, The latter rises by 

 two slips from about the middle of the inner surface of the mandible 



