136 REPTILIA. 



into a rounded condyle for articulation with the inferior maxilla. 

 This bone is similar in character, only narrower, in the Sauria, still 

 more elongated in the Ophidia, and in both, especially the latter, 

 moveably united to the mastoid bone. The parietal bone is double 

 in the Tortoises, but throughout almost all the Ophidia and Sauria, 

 as in the Crocodiles, and even the anomalous genus, Amphisbaena, 

 it consists of a single usually insignificant bone. The two frontals 

 are still smaller, and united by a suture in the Chelonia, Ophidia, 

 and some Sauria ; the Crocodiles and other Sauria have a single 

 frontal. A pair of bones situated in front of the frontals, frequently 

 separated, as in the Ophidia and Crocodiles, by the nasal bones, may 

 be regarded as ethmoidal, or according to others nasal bones. They 

 appear to be absent in other Reptilia. 



The Facial bones exhibit fewer deviations from their normal 

 type in the higher Vertebrata, and admit, therefore, for the most 

 part, of being readily and consistently referred to their analogues in the 

 human subject. In front of the frontals lie generally a pair of mostly 

 elongated nasal bones, there being very rarely only a single bone 

 in their place, as in Moniter niloticus. Between the squamous 

 element of the temporal and the superior maxilla the jugal bone is 

 intercalated ; it is of very large size in all the Chelonia and Croco- 

 diles, and is met with in the rest of the Sauria, but appears to be 

 absent in the Ophidia, and its place to be supplied by the external 

 wings of the sphenoid. The palatal bones are very generally 

 present, situated between the pterygoid processes and the superior 

 maxilla, and are broad in the Chelonia, very elongated and mostly 

 furnished with teeth in the Ophidia. Between the superior max- 

 illary, nasal, ethmoid, and jugal bones, there is introduced, as in the 

 Crocodile, a bone of tolerably large size, which may be either 

 regarded as a distinct bone by itself, or from the analogy of its 

 position, as a lacrymal bone. It would appear to be absent in the re- 

 maining Reptilia. The vomer is in the majority of instances, as in 

 the Ophidia and Sauria, of large size and double ; in the Crocodile, 

 however, it is absent. In the Chelonia this bone is single, and 

 frequently concealed from beneath by the palatal bones. Those bony 

 plates, called ossa supsrciliaria s. squama supra-orbitales, which are 

 placed in the Lizards upon the edge of the frontal bones, and 

 form the roof of the orbitar cavity, are rather to be considered as 

 pertaining to the tegumentary skeleton, than as true bones of the 

 face. The intermaxillary bone is generally small and single in the 

 Ophidia, Sauria and Matamata Turtle (Chelys) ; but double in the 



