CROCODILIANS, LIZARDS, AND SNAKES. 163 



zygomatic (quadratojugal) to the supratemporouiastoid and postfiontal 

 is equally peculiar to it. Another peculiarity is tlie non-entrance of the 

 exoccipital bone into the occipital condyle. Another remarkable pecu- 

 liarity is the union, a short distance below the brain case, of the Eusta- 

 chian tubes into a single median vertical canal, which descends to the 

 l^harynx between the vertical axes of the basioccipital and sphenoid 

 bones. 



The mandibular ramus is characterized by the distinctness of all the 

 elements and by two especial peculiarities. One of these is the absence 

 of coronoid process, the coronoid bone being a scale on the interior side 

 of the ramus. The other is the presence of a very large foramen 

 between the angular and surangular bones on the external face of the 

 ramus, which communicates with the large dental canal. 



The vertebme are procoelous throughout. There are no intercentra 

 except the chevron bones and a preatlantal element, which articulates 

 with the lower part of the occiijital condyle in front, and underlaps the 

 OS entatum, or centrum of the atlas ; posteriorly. This first and only cer- 

 vical interceutrum sends out, posteriorly and downward on each side, a 

 long intercentral rib. The atlas consists of separate elements, viz, 

 centrum, nenrapophysis, and neural spine. The centrum is united by 

 suture with that of the axis vertebra, and the neurapophyses are in con- 

 tact anteriorly below with the intercentrum. They narrow upward to 

 a squamosal suture with the neural spine, which is a thin, curved ele- 

 ment. The cervical ribs are short, and unite with a parapophysis and 

 diapophysis. The dorsal ribs have tlie capitular articulation on the 

 centrum, and the tubercular on the diapophysis for a short distance, 

 but the capitular articulation soon rises to the diapophysis, remaining 

 distinct from the tubercular. There are two sacral vertebrae, and no 

 sacral ribs. 



There is no clavicle, proscapula, or epicoracoid. The coracoid is in 

 contact with the anterior lateral border of the sternum. The supra- 

 scapula is represented by a cartilage. The ilium is short auteroposte- 

 riorly and does not extend anteriorly to the acetabulum, but does 

 extend for a short distance posteriorly to it. The pubis is excluded 

 from the acetabulum, articulating with the anterior base of the 

 ischium. The pubes are directed forward and have no symphysis, being 

 connected by cartilage only. They have no connection with the ischia 

 on the median line. The ischia are directed downward to a median 

 symphysis. 



There are three elements in the proximal carpal series. Of these the 

 radiale and intermeduim support the foot, and are remarkable for their 

 longitudinal elongation. The cari)alia are more or less aborted. The 

 tarsalia are remarkable for tlie specialization of the bones of the first 

 row. They are two in number; the large astragalus consisting, appar- 

 ently, of the tibiale and intermedium tarsi. The fibulare (calcaneum) 

 has what has not been shown to exist elsewhere among Eeptilia, a tuber 



