CROCODILIAXS, LIZARDS, AND SNAKES. 457 



like portion. Epipterygoid extending from the pterygoid at the basi- 

 pterygoid process, and resting on tbe apex of the petrosal. Latter 

 produced above anterior to semicircular canal; tbe anterior border con- 

 tinued into a crest which runs posteriorly above tbe trigeminal foramen. 

 This terminates at the down-looking crest of the subforaminal portion, 

 which bounds externally a wide down-looking groove. Basipterygoid 

 j)ro(;esses long. Sphenoid distinct from basioccipital. Occipital con- 

 dyle subequally divided into three parts, two prominent exoccipitals 

 and a contracted basioccipital. The result is an apparently double 

 condyle. 



Mandible with the Meckelian groove closed, and with the splenial 

 small and but little produced beyond the splenial foramen. Coronoid 

 produced a little horizontally at the base. Angular not distinct; surau- 

 gular and articular distinct. Angle simple, direct, spoon-shaped, with 

 superior concavity. 1 have observed the following peculiarities in the 

 otic and hyoid regions. There is no infrastapedial cartilage, and the 

 suprastapedial and epistapedial cartilages are continuous. The hyoid 

 system is characterized by the fact that the ceratohyal is attached to 

 the paroccipital, which carries a cartilage on its extremity. There is a 

 short second ceratobranchial, and no free epibranchial. 



Vertebra' amphicoelous, Intercentra present throughout the verte- 

 bral column, continued into chevrons on the caudal region. Cervical 

 ribs widened and truncate at extremities. In the specimen described 

 the diapophyses of the second sacral vertebra are deeply longitudinally 

 grooved on the inferior side so as to be nearly split. Diapophyses of 

 anterior caudals elongate. Neural spines distin(;t but low throughout 

 the column. In the scapular arch I note the following peculiarities. 

 There is no proscapula, and the clavicle is much enlarged, and is per- 

 forate at the median extremity. The interclavicle is cruciform, with the 

 angles tilled up so as to have concave borders. It is coossified with the 

 clavicle in P. tuberculatus, and extends but a little way posteriorly on 

 tbe sternum. The coracoid has one large foramen. The sternum has 

 no fontanelle. There are four luemapophyses attached to the sternum 

 on each side; and two to each of the slender closely approximated 

 xiphoid rods. There are several very slender abdominal ribs. 



The ilium has no angulns crista; and the acetabulum is entire. The 

 pubes join at a little less than a right angle, and the jtectineal processes 

 are short and a little posterior to the middle. Pubes uniting at less 

 than a right angle below, with the tuberosities distal. 



The most distinctive feature of the skeleton of this genus is the pres- 

 ence of intercentra throughout the vertebral column, a point in which 

 it resembles the extinct Theromora of the Permian epoch. 



