214 



THE EXTINCT BATRACHIA, REPTILIA 



The pterygoids are both wider and longer than the palatines. 

 curved inwards and upwards — the outer thinned away. They narrow gradually poste- 

 riorly, the outer margin bordering the bases of the teeth opposite the ectopterygoid. The 

 latter is attached to a strong external transverse process of the pterygoid. It presents an 

 inferior angulation and bends anteriorly, where it is so thinned out as to suggest its dis- 

 continuance. The transverse; process is continuous with an upper plane of the bone, and 

 spreads from the upwards rolled inner margin. The posterior parts of both pterygoids 

 are broken away. There is no scar or fossa for columella. 



The ossa quadrata are preserved and in good condition. There are two concave faces, 

 the largest directed inwards, and the lesser directed outwards and backwards. The bone 

 sends forwards a broad ala, with convex crenate margin, which bounds the larger. The 

 meatus pierces or is enclosed by the outer, by the posterior curvature of the supero-poste- 

 rior process. The superior articular surface is much more extensive than the inferior, and 

 is tripodal; the posterior branch articulates with the opisthotic. The inferior articular 

 face is sub-transverse, or directed forwards and inwards. It is constricted in the middle, 

 the outer portion the smaller. 



The cotylus of the mandible is also obliquely transverse, the inner portion deeper in 

 order to receive the large condyle of the quadratum. 



The mcmdiMe of course partakes of the exceedingly elongate form of the cranium, rel- 

 atively exceeding Mosasaurus in this respect. 



The fossa for the temporal muscle is .large and deep, but without inner wall. The 

 coronoid process elevated, convex and rugose interiorly, and with a deep longitudinal 

 groove exteriorly. The superior margin of the coronoid bone is concave, and broad. The 

 dentary terminates in a peculiar striate plug posterior to the last tooth. The distal third 

 or less, is strongly grooved for Meckel's cartilage ; proximally this is concealed by the 

 very long laminiform splenial. 



The splenial is largely developed on the outer lace of the ramus, where it articulates 

 with a, bone whose homologies are somewhat uncertain. 



The xubarticAilar has a narrow and inferior exposure on the external face of the ramus, 

 and meets the angular just in front of a point opposite the anterior margin of (he glenoid 

 cavity. Interiorly it is a little more elevated, but only opposite to the coronoid process : 

 behind and above this it is restricted by the long anterior process of the angular. Ante- 

 riorly it is terminated by the squamosal suture of what may be the splenial, just below tin; 

 first rise of the coronoid process. 



The angular furnishes the floor for the cotylus for the quadratum. Inwardly it is 

 concave longitudinally, but does not send any horizontal process inwardly: its angle is 

 obtuse'; above broad and oblique. Exteriorly it gives way to the large articular. In- 



