REPORT ON THE SPHENISCID^. 131 



Nerve supply (?) 



Variations. — In the different species of Spheniscus whicli I have examined, I find 

 the origin of this muscle more extensive than in other genera, its origin reaching 

 the upper surface of the skull, and coming into close relation with the muscle of 

 the opposite side. In them, also, its origin extends farther forwards than in the species 

 of other genera, so much so that the origin of the digastric to a considerable extent 

 overlaps that of the temporal muscle. 



2. Temporal muscle. 



Le Masseter, Vicq d'Azyr, 1773, p. 584, No. 2. 



Der Schldfemmiskel, Tiedemann, p. 385, No. 1. 



Der Schlafenmztskel, Wiedemann, p. 72. 



Masseter et Crotaphite, Cuvier, vol. iii. p. 70. 



L'elevateur de la mdehoire inferiewre, Meckel, vol. viii. p. 161, No. 1. 



Le temporal, Gervais and Alix, p. 19. 



Attachments. — The temporal muscle anses by means of two heads, a superficial and 

 a deep. The superficial head arises, without the intervention of tendon, from the whole 

 of the depressed lateral surface of the skull (temporal fossa) situated between the trans- 

 verse occipital crest behind and the post-orbital process in front. The deep head arises 

 by means of a pointed tendon from the lower surface of the projecting ledge of bone which 

 overhangs the quadrato-temporal articulation. This tendon gives place to muscular 

 fibres, which, after passing beneath the zygoma, are hiserted along with, but behind that 

 of the superficial head into the outer surface of the ramus of the lower jaw. The attach- 

 ment of both heads into the lower jaw extends from the quadrato-maxillary articulation 

 behind, to the angle of the mouth in front. 



Action. — This muscle is the principal elevator of the lower jaw. 



Relations. — This muscle is overlapped behind by the digastric, from which it is separ- 

 ated by the auditory passage. The deeper head is concealed at its origin by the super- 

 ficial, but at its insertion lies alongside of, and behind the latter. 



Nerve supply (?) 



Remarks.- — The deep portion of the muscle, as above described, is the " faisceau zygo- 

 matique " of Gervais and Alix. 



3. Pterygoid muscle. 



Le muscle abaisseur du bee superieur, Herissant, 1748, p. 345. 



Der Fliigelmuskel, Wiedemann, p. 74. 



Der Flugelmusliel, Tiedemann, p. 388, No. 6. 



Pterygoldien, Cuvier, vol. iii. p. 72. 



Muscle No. 3, Meckel, vol. viii. p. 161, No. 3. 



Pterygdidieii, Gervais and AUs, p. 19. 



