26 POSTBBIOR CRANIAL ARCHES IN THE REPTILIA. 



Fig. 1. Naosaurus daviger Cope, } nat. size ; muzzle and lower jaw wanting, but restored from allied species ; 

 zygomatic arch partly wanting ; left side ; a, from above. Coll. E. D. Cope. 



8. Diopens leptocephalus Cope, ^ nat. size ; supratemporal, zygomatic and quadrate bones ; left side. Coll. 



E. D. Cope. 



9. SpJienodon punctaium Gray, skull f nat. size ; right side. Coll. E. D. Cope, from Sir James Hector, New 



Zealand. 



Plate III. 



DiCLONiTJS MiEABiLis Lcidy ; stull about one-fourth natural size, from side and above. 



Plate IV. ^ 



Diagrams op Skulls of the Theromoko-stkeptosttlicate series ; vertical and side views, based on Pantylus 



cordatus. 

 Mg. 1. Theriodonta. Fig. 2. Pseudosuchia (from Zittel). Fig. 3. Rhynchocephalia. Fig. 4. Anomodontia. 



Fig. 5. Lacertilia. Fig. 6. Ophidia. 

 The supramastoid-parietal suture is omitted in the Pseudosuchia to resemble Aetosaurus. The supratemporo- 



supramastoid suture is omitted in the Rhynchocephalia in imitation of Sphenodon. All the teeth but 



one are omitted from the Anomodonta, in imitation of Dicynodon. 



Plate V. 



The Archosatjrian and Stnaptosaurian Series ; Diagrams op Skulls, based on Pantylus cordatus. 



Fig. 1. Ichthyosauria. Fig. 2. Crocodilia (Teleosaurus). Fig. 3. Dinosauria (Diclonius). Fig. 5. Sauropterygia 



(Nothosaurus). Fig. 5. Testudinata (Chrysemys). Fig. 6. Testudinata (Trionyx). 

 In the Crocodilia and Dinosauria the supratemporal is omitted, and in Sauropterygia it is fused with the supra- 



mastoid. In Testudinata the supramastoid is omitted. In Dinosauria the postorbital and postfrontal 



are represented as fused, although this may be an appearance only. 



EXPLANATION OF LETTERING. 



Pmx., premaxillary bone ; Mx., maxillary ; J., jugal (malar) ; Z., zygomatic (quadratojugal) ; L., lachrymal ; 

 iV., nasal ; F, frontal ; Pef., prefrontal ; Pof., postfrontal ; Poi., postorbital ; P., parietal ; Sm.. supramastoid ; St., 

 supratemporal ; Int., intercalare ; So., supraoccipital ; Bo., basioccipital ; Q., quadrate ; Pg., pterygoid ; Stop., Stapes. 



