Cranial Characters of Ljuanoid f.izards. 413 



2. Conolophus, Fit/,.*— All the teeth trilobate. Pn\3- 

 niaxillaiy not extciKlinj:; as tar as the posterior border of the 

 nasal fossae ; the lenj^th of the latter nearly equals their 

 distance from tlie orbits. Prefrontal not entering the nasal 

 fossa. Postfronto-sqnaniosal arch longer than the orbit; 

 postfrontal longer than dccji. Transpalatinc in contact with 

 palatine. Basisjihenoid short and nnich constricted behind 

 the basiptcrygoid processes, as in the preceding. 



3. Brachylophis, Wagl. — All the teeth tricuspid. PrjK- 

 niaxillary not extending as far as the posterior border of the 

 nasal fossa3 ; the length of the latter equals their distance 

 from the orbit. Prefrontal not entering the nasal fossa. 

 Postfronto-squaniosal arch short, not longer than the orbit ; 

 postfrontal as long as deep. Transpalatinc not in contact 

 with palatine, l^asisjiiienoid as in Cydura^ rather elongate 

 and much constricted behind the basiptcrygoid processes. 



4. Iguana, Laur. — Lateral teeth with numerous denticles. 

 Premaxillary not extending as far as the posterior border of 

 the nasal fossa? ; the length of the latter nearly equals their 

 distance from tlie orbits. Prefrontal not entering the nasal 

 fossa. Postfronto-squamosal arch slender, short, not longer 

 than the orbit ; postfrontal as long as deep. Transpalatine 

 in contact with palatine. Basisphenoid short and but slightly 

 constricted behind the basiptcrygoid processes. 



5. Metopocerosj Wagl. — Lateral teeth with four to seven 

 cusps. Premaxillary not extending as far as the posterior 

 border of the nasal fosse ; the length of the latter much 

 greater than their distance from the orbits. Prefrontal entering 

 the nasal fossa. Postfronto-squamosal arch wide, a little 

 longer than the orbit ; postfrontal longer than deep. Trans- 

 palatine not in contact with palatine. Basisphenoid inter- 

 mediate between Iguana and Cyclura. 



6. Cyclura, Harl. — Lateral teeth with three to six cusps. 

 Premaxillary extending as far as the posterior border of the 

 nasal fosse ; the length of the latter not more than their 

 distance from the orbits. Prefrontal not entering the nasal 

 fossa. Postfronto-squamosal arch long and wide, intermediate 

 between Metopoceros and Ctenosaura ; postfrontal longer thart 

 deep. Transpalatine not in contact with palatine. Basi- 



* The cranial characters are taken from the figure gi\en by Steiu- 

 dachner, Fe.itfchr. zool.-hot. Ges. Wien, 1876, pi. v. 



