1 8 THE OSTEOLOGY OF THE REPTILES 



and maxillae, above with postorbitals, and, by an extensive over- 

 lapping suture, with the squamosals and quadrate jugals; on the inner 

 side perhaps with the ectopterygoids. 



Absent in some Ophidia (Fig. 59 b) and some lizards (Fig. 56). In 

 the lizards (Fig. 55) they may not articulate with the squamosals. 



Intertemporals {it) . An amphibian bone known only in Seymouria 

 (Figs. 2, 19) of the Cotylosauria, intercalated between the post- 

 frontal, parietal, supratemporal, and postorbital. 



Supratemporals {st). Primitively (Figs. 2, 4, 19) articulating at 

 the sides of the parietals with the postfrontal and postorbital an- 

 teriorly, the tabulars behind, and the squamosals on the outer side; 

 interrupted by the otic notch in Seymouria (Figs. 2, 19). 



Absent in the more specialized Cotylosauria, probably all Thero- 

 morpha, and all other reptiles save possibly the Ichthyosauria (p. 62) 

 and Squamata (p. 65). Generally known as the posterior bone 

 of the arch in the Squamata (Fig. 55 a, to). [But see tabular 

 below.] 



Tabulars (/). Primitively (Figs. 2, 4, 22) on the dorsal surface of 

 the skull in the Cotylosauria, as in the Amphibia, at the outer side 

 of the interparietals, articulating with the squamosals and supra- 

 temporals, with the upper end of the quadrates and the outer end of 

 the paroccipitals, whence the name ''paroccipital plates" given to 

 them by Baur. They are known to be absent in but a single genus of 

 Cotylosauria; are probably present in most Theromorpha (Figs. 

 33 B, 42 d) and Therapsida (Fig. 44 g), and some " Pseudosuchia " 

 (Fig. 65 c). The tabular has been identified by the author as the 

 posterior bone of the arch in the Squamata (p. 62), and Ichthy- 

 osauria (p. 62), usually and perhaps correctly called the supra- 

 temporal. It is unknown in other reptiles. 



Squamosals (sq). Primitively (Figs. 2, 4) articulating with tabu- 

 lars and supratemporals above, in the absence of the latter directly 

 with the parietals (Figs. 33 a, 53 a). Below, they cover the posterior 

 part of the temporal region, extending back of the quadrate to articu- 

 late with the pterygoids (Fig. 7), overlapping extensively the quadra- 

 tojugals on the sides (Fig. 33 a), and articulating in front with jugals 

 and postorbitals. 



In later reptiles the squamosal has undergone many changes, but 

 is always present, though sometimes vestigial in the Chelonia, 



