CROCODILIANS, LIZARDS, AND SNAKES. 685 



ward, which gives articulation to the quadrate, bounding the fenestra 

 ovalis above. The latter is large and is closed by the large disk of the 

 stapes. The quadrate has no posterior proximal process, and is oblic^ue 

 proximally, but is nu)re nearly vertical distally. In its i)Osterior angle 

 rests the club-shaped head of the robust columella auris. 



The vomer presents at its auterior extremity a process which separates 

 a transverse process frou) each maxillary, and enters a not<;h in the 

 posterior border of the premaxillary. The vomers are jilane in front, 

 but become convex and separated by a fissure posteriorly, ending each 

 in an acuminate apex lying on the presphenoid. The palatine is nar- 

 row and lies along the inner side of the ectopterygoid, consisting chiefly 

 of its maxillary process; it is doubtful whether it possesses a vomerine 

 process. Posteriorly it lies scale-like on the pterygoid, reaching nearly 

 to the line of the quadrate. The narial fissure is nearly closed anteriorly, 

 except a foramen-like portion at the anterior extremity. The presphe- 

 noid, sphenoid, and basioccipital are coossified. To these the pterygoid 

 is closely appressed by the one side, while on the outer side the latter 

 carries the narrow splint-like ectopterygoid as far as the maxillary. 

 No palatine foramen. Occipital condyle simple, transverse, medially 

 concave. 



The mandible displays noMeckelian groove, and the splenial is small. 

 The small angular is only visible on the in ternal side of the ramus. Sur- 

 angular and articular confluent. Coronoid large, triangular, not concave 

 below, and overlaid at base externally by anterior extremity of surangu- 

 lar; anteriorly not extended over dentary. Angle short, longer than 

 wide, a little inflected, simple; its plane an angle of 45 degrees to that 

 of the ramus. 



The hyoid apparatus is very simple. It consists of a glossobasihyal 

 cartilage which is deeply bifurcate posteriorly. At the posterior extrem- 

 ity each posterior limb sends a process forward, which is about half as 

 long as the antei'ior elements, the hypohyal. Xo ceratohyal nor second 

 ceratobrancliial. A rather short and simple osseous flrst ceratobran- 

 chial on each side. 



The vertebral column consists of manycervico-dorsals and a relatively 

 small number of caudals. The second vertebra has a strong keel-like 

 hypapophysis, which is also strong on the third, but which diminishes 

 from that point so that on the sixth it is no longer perceptible. The 

 first rib is short and is attached to the third vertebra. Diapophyses 

 and neural spines very short. The ribs do not disi)lay a vertical process 

 at the head as in Lepidosternum octostegum. Diapophyses very short 

 and simple on caudal vertebrae. Caudal hypapophyses beginning on the 

 anterior fourth of the caudal series, the halves at first widely sepa- 

 rated. They soon converge downward, and finally touch, but are never 

 coossified to form a chevron. Position on the middle of the length of 

 the centrum. Rib-bearing vertebra' without trace of zygosphen. 



Scapular arch absent. Pelvic arch represented by a single curved 



