SKULL — REPTILES 



153 



capsule to the supraseptal wall, and ventral to this is a medial parietal taenia, also 

 extending from the supraseptal plate to the prootic pillar, bounding the metoptic 

 fenestra above. These two taeniae are joined by a vertical bar which extends 

 down to the common trabecula. In Eumcces only the part of this bar below the 

 medial teenia is present. Apparently both taeniae and the vertical bar are the 

 homologues of the Elasmobranch sphenolateral. 



Fig. 162. — Chondrocranium and early membrane bones of Eutneces s-Hnealus 

 (Rice, '20). cl, columella; cp, paraseptal cartilage; ep, epipterygoid; /, frontal; fe, 

 endolymph foramen ;//z, fenestra hypophyseos;/m, foramen magnum ;/o, optic foramen; 

 h, hypochiasmatic bar; ios, interorbital septum; m, maxillary cartilage; w, nasal; of, 

 olfactory foramen; p, parietal; pa, ascending process; pc, anterior pterygoid cartilage; 

 pf, postfroVital; pi, palatine; po, postorbital; pp, posterior pterygoid cartilage; prf, 

 prefrontal; pt, pterygoid bone; q, quadrate; 5, nasal septum; sc, sellar crest; sf, septal 

 fenestra; si, sphenolateral; sq, squamosal; s.s, supraseptals; I, transversum; tr, trabecule- 

 V, vomer; 3, zygomatic. 



The upper margin of the supraseptal plate is connected with the nasal capsule 

 by a slender sphenethemoid bar. The capsule has a strong internal process 



