GREGORY: FISH SKULLS 



TABLE I — Continufd 



89 



Orbitosphenoid 



"Alisphenold" (pterosphenoid, De 

 Beer, 1926) 



covered dorsallv by 



Frontal 



"Postorbitals": cheek plates covering the adductor man- 

 dibulae muscles laterally in semionotids, Lepidosleu.<, 

 primitive amioids, etc.; lost in teleosts (sometimes 

 wrongly called suborbitals); not equivalent to true 

 postorbiial of tetrapods, which is derived from the 

 inner or circumorbital row. 



Sphenotic 



Pterotic 



(3) Otic Region 

 covered dorsolaterally by Dermosphenotic ("so 6") 



covered laterodorsally by 



"Pterotic" (often fused with true pterotics; bearing part 

 of the supratemporal canal ="supratemporal of tetra- 

 pods; incorrectly called squamosal) 



Parietal 



Otic capsule 



Prootic 



Opisthotic 



Exoccipital (often 

 conibined with 

 opisthotic) 



Epiotic 



often covered by and com- 

 bined with 



"Epiotic" (superiiciaO 



Supraoccipiial (tec- 

 tum synoticum) often covered by and com- 

 bined with 



"Basisphenoid" 

 Basioccipital 



B. Endocn'athal 



"Supraoccipital" (= dermosupraoccipital) 



"Scale bone" (tabular, extrascapular, "supratemporal" of 

 Owen, Ridewood and Starks) covering posttemporal 

 bone 



Posttemporal (connecting pectoral girdle with skull) 

 (4) Basicranial Region 

 covered ventrally by Parasphenoid ( = vomer of mammals) 



II. BRAN'CHIOCRASItrM 



B' Dermognathal 



(1) Oromandibular Region 



(? Labial cartilages of elasmobranchs] replaced by 



Primar>' Upper Jaw (Palatoquadrate) 

 comprising: ' 



(a) Autopalatine ("palatine," 



from anterior supraterj'goid) covered ventrally by 



(i) Suprapterj'goids (from 5 to 

 2, upper part of palato- 

 pter\goid of primitive pal- 

 SBoniscids, probably lost in 

 teleosts) 



(f) Metapterygoid (posterior end 

 of palatoquadrate, con- 

 nected with hyomandibular) 



'See Watson, D. M. S., Proc. Zool. Soc. London, 1925, pp. 851-862. 



'Secondar>- upper jaw" (premaxilla, supramaxillae 1, 2, 

 maxilla) 



Dentigerous palatine I (in primitive palaeoniscids) 



