215 



length, but furnished with large claws, twisted outwards ; maxillary 

 bones articulated posteriorly by suture to the palatine, its malar pro- 

 cess thick, rounded anteriorly ; malar bone but slightly angular, its 

 zygomatic process extending beneath the zygoma ; palatine bone 

 ascending into the orbit, and pushing up the sphenopalatine foramen 

 into a fossa which contains the foramina of the orbit ; pterygoid 

 bones with their hamular processes styliform, projecting backwards ; 

 zygoma small, rounded above ; tympanic incompletely ossified ; mas- 

 toid bone broad, placed obliquely ; lower jaw slender, its condyle 

 elevated, reniform ; coronoid process feebly developed, lower than the 

 condyle. 



X. TJNICINCTUS. 



CuTier mentions a species with a shorter and more entirely naked 

 tail ; it is probably the same that has been called nudicaudis by Dr. 

 Lund. X. antiquus of the same distinguished author may possibly 

 be identical. 



Priodontes, Frederick Cuvier. 



Head broad behind, ears wide apart ; plates of the head and body 

 as in Xemirus ; tail closely covered with quadrangular scales, placed 

 in a quincuncial arrangement ; fore-feet as in Xenurus, the outer toe 

 much reduced ; maxillary bone articulated posteriorly by suture to 

 the palatine ; teeth numerous and minute ; infra-orbital canal long, 

 commencing below the malar process, and terminating nearly on the 

 middle of the bone ; malar bone forming simply a portion of an in- 

 verted arch, round, and devoid of processes ; palatine bone ascending 

 into the orbit ; pterygoid bone strongly developed, with an angular 

 termination; zygoma rather small, the glenoid surface lengthened, 

 the lower part of the squamous and the alisphenoid bone forming a 

 longitudinal swelling within it ; tympanic bone small, and loose ; 

 mastoid bone broad, forming the sides of the occipvit which are 

 rounded ; lower jaw thin and compressed, condyle longitudinal, but 

 little elevated ; coronoid process much reduced. 

 P. gigas. 



ToLYPETJTES, Illigcr. 



Head broad behind, ears wide apart ; plates very closely articulated 

 to each other, their surface divided by impressed marks, and studded 

 with blunt tubercles, those of the scapular and pelvic shields varying 

 from a square to a pentagonal or hexagonal form ; bands three, com- 

 posed of oblong parallelograms, equally subcircular, and closely arti- 

 culated ; fore-feet four-toed, the outer being absent ; the medius 

 slightly longer than the index, with a much larger claw, both having 

 an outward twist ; maxillary bone articulated posteriorly to the pala- 

 tine, its malar process standing suddenly outwards, compressed ; infra- 

 orbital canal commencing below and behind its root, rather lengthened, 

 rising a little in its course ; teeth rather large ; malar bone slender, 

 and simply abutting by an oblique suture against the zygoma ; pala- 

 tine bone ascending into the orbit, pteiygoids with blunt hamular 



