Page:The Osteology of the Reptiles.pdf/38

20 in the Squamata (Figs. 55, 56 ) they articulate with the palatines only, as also in some Chelonia (Figs. 31 , 32 ) and Plesiosauria (Fig. 46 ). Generally believed not to represent the unpaired vomer of the mammals.

Palatines (pl). Primitively (Figs. 6, 21) forming the posterior boundary of the internal nares, articulating with the prevomers and pterygoids on their inner sides, the maxillae on their outer, and with the descending process of the prefrontals above. More or less dentigerous.



Teeth are still present in the Theromorpha (Figs. 40, 42 ) and some Therapsida, but are lost in other reptiles except the Rhynchocephalia (Figs. 62 , 63 ) and most Squamata (Fig. 54 ). They may join in the middle in the Chelonia (Figs. 31, 32 ) and in the Crocodilia (Fig. 69 ) below the prevomers.

Pterygoids (pt). (Figs. 6, 7, 21, 40 .) Bones of the posterior part of the palate, articulating with the prevomers in front, the palatines and ectopterygoids laterally, the basisphenoids on the inner sides, the quadrates and squamosals posteriorly. Dentigerous.

As stated above they do not articulate with the prevomers anteriorly in the Squamata and many Chelonia and Plesiosauria, but do articulate with the parietals in many Chelonia. Their connection