HEAD-MUSCLES IN GALLUS AND OTHER SAUROPSIDA. 553 



Lower portion, inner division — 

 Pterygoid (undivided) : 



Chelonia — pterygo-maxillaris (H). 



Crocodilia — pterygo-maxillaris (H). 



Rhiptoglossa — pterygo-maxillaris (H). 



Opliidia — trans verso-maxillo-pterygo-mandibularis (H). 



Internal pterygoid : 



Birds — pterygoideus internns (G). 

 Sphenodon — pterygoideus internus (Oj. 

 Lacertilia vera — pterygoideus internus (H) = pterygoideus (V) 

 = pterygo-mandibularis (B). 



External pterygoid : 



Birds — pterygoideus externus (G). 

 Sphenodon — pterygoideus externus (0). 

 Lacertilia vera — pterygoideus externus (H) = pterygoideus (B). 



Lower portion, outer division — 



Temporal and quadrato-maxillaris : Birds (G). 

 Temporal : 



Chelonia — occipito-squamoso-maxillaris (H). 

 Crocodilia — temporalo-maxillaris (H). 

 Sphenodon — capiti-mandibularis (O). 

 Lacertilia vera — temporalis (H):=capiti-mandibulari.s (B). 

 Rhiptoglossa— temporo-mandibularis et quadrato-mandibularis (H). 

 Ophidia — parieto-quadrato-mandibularis (H). 



Hyoid myotome — 



Stapedius: Birds (G), Alligator (K), Lacerta agilis, L. viridis, and 



Zootoca vivipara (P). 

 Depressor mandibulae : 



Birds — digastricus (G). 

 Chelonia — squamoso-maxillaris (H). 

 Crocodilia — occipito-maxillaris (H). 

 Sphenodon — parieto-mandibularis (0). 

 Lacertilia vera — digastricus (H) = depressor mandibulie, (V) = parieto- 

 mandibularis (B). 

 Rhiptoglossa — depressor maudibulse (H). 



Ophidia — occipito-quadrato-mandibularis (H). 



First branchial myotome — 



Branchio-hyoideus, branchio-maxillaris : 

 Sphenodon — cerato-hyoideus (0). 



