EXPLANATION OF THE PLATES. 333 



EXPLANATION OF THE PLATES. 

 PLATE VI. 



Fig. 1. Upper surface of cranium of Anthracosaurus Russelli, one third 

 the natural size; P.max, premaxilla: M.g, mucus -groove ; A.n.o, 

 anterior nasal orifice ; N, nasal bone ; Max, maxilla ; L, lacrymal 

 bone; Ju, jugal; Qu.ju, quadrate-jugal ; Qu, Quadrate; S.t, supra- 

 temporal ; 0. V, orbital vacuities ; Fr, frontals ; Pr.fr, prefrontal ; 

 Pt.fr, postfrontal ; Pt. 0, postorbital ; P, parietals, with parietal 

 foramen ; Sq., squamous ; S.O?, supraoccipital, so called ; E, epiotic; 

 T.F, temporal fossa ; S.O, supraoccipital; E.S, exoccipital; Mand, 

 anterior end of left mandible overlying part of skull ; P.B, palate - 

 bone, posterior end of right side, displaced. 



Fig. 2. Upper, and fig. 3 under, surface of a dermal scute; a, anterior 

 end. 



PLATE VII. 



Under surface of same cranium, one-third the natural size. P.max, pre- 

 maxilla ; V, vomer ; N. C, nasal channel ; Max, maxilla ; Pal, 

 palate- bone ; P.T, palate-tusk; P.t.p, palate-teeth, small posterior 

 series; O.V, orbital vacuities; Pter, pterygoid-bone ; B.sph, basi- 

 sphenoid ; Pr.sph, presphenoid ; Pf.fr, prefrontal ; L, lacrymal ; 

 Ju, jugal ; Qu.ju, quadrate-jugal ; B.oc, basioccipital ; Qu, quad- 

 rate ; Mand, right ramus of mandible overlying part of right side 

 of skull. 



PLATE VIII. 



Fig. 1. Inner surface of right mandible of same, one third the natural 

 size. Ar, articular piece ; D, dentary ; S, splenial ; An, angular ; 

 Sym, symphysis. 



Fig. 2. Outer surface of left mandible, one third the natural size. Ar, 

 articular piece ; D, dentary; An, angular; M.g, mucus-groove. 



Fig. 3. Dorsal rib, two thirds the natural size. 



Fig. 4. Dorsal vertebra, natural size, entire. 



PLATE IX. 



Sections of Teeth of Anthracosaurus. 



Fig. I. Transverse section of maxillary tooth near to apex and above pulp- 

 cavity, magnified 12 diam. E, enamel ; D, dentine. 



