SKULL AND OTHER BOXES OF LOXOMMA AXLMANNI. 225 



place in the scale of animals somewhere between Fishes and Rep- 

 tiles, between the Salamandroid fishes and the Crocodilia; for 

 whilst it resembles most the Labyrinthodontia, it possesses cha- 

 racters, more or less important, in common with all the orders 

 lying between Granocephala and Crocodilia. 

 , It clearly links together, in a very remarkable manner, the 

 two great classes of Fishes and Eeptiles, and adds fresh confirma- 

 tion, if indeed such were needed, to the opinion of Professor 

 Owen, that " other extinct orders, Ganocephala and Labyrin- 

 thodontia, have demonstrated the artificial nature of the distinc- 

 tions between Fishes and Reptiles, and the close transitions that 

 connect together all the cold-blooded vertebrates." 



EXPLANATION OF THE PLATES. 



PLATE I. 



Upper surface of cranium of Loxomma Allmanni, half the natural size. P. 

 max, premaxillary bone ; M.g, mucus - grooves ; A.n.o, anterior 

 nasal orifices ; 2V, nasal bones ; Max, maxillary bone ; L, laciymal ; 

 Ju, jugal; Qu.ju, quadrate jugal ; Qu, quadrate ; S.t, supratempo- 

 ral ; O.v, orbital vacuities ; Fr, frontal bone ; Pr.fr, prefrontal ; 

 Pt.fr, postf rontal ; Pt. o, postorbital ; P, parietals, with parietal 

 foramen ; Sq, squamous ; S.o V, supraoccipitals, so-called ; Mast, 

 mastoid ; Tf, temporal fossa ; S.o, supraoccipital ; Ex.o, exocci- 

 pital. 



PLATE II. 



Under surface of cranium of Loxomma, half the natural size. P.max, pre- 

 maxillary bone; V.t, vomerine tusks; P.p.v, palate-plates of vo- 

 mers; P.p.p, palate-plates of palate-bones; P.p.max, palate-plates 

 of maxillaries ; A.max, alveolar border of maxillary ; Ap, aperture 

 in palate ; P.t, palate-tusks ; Sect, section of this tooth shown in 

 Plate IV., fig. 5; Ju, jugal; Qn, quadrate; Pter, pterygoid; E, 

 ridge on median line between palate and pterygoid bones ; Ec.pter, 

 ectopterygoid ; B.sph, basisphenoid ; P.n.o, posterior nasal orifices ; 

 B.oc, basioccipital ; Ar.cav, articular cavity of ditto for atlas ; F.exoc, 

 facets of exoccipital for arches of atlas. 



