Fig. i. 



A ' "S^T? 011 an r vertehral column of the Frog, viewed from the dorsal surface. 

 >, 1 1 e same from the ventral surface. C, Lateral view of the urostyle ; a bristle 

 is passed through the foramen for the tenth spinal nerve. J), The branchial 

 skeleton of the Frog. (All the figures after Eckcr.) O, orbital fossa ; ////.r, 

 premaxilla; inx, maxilla; q.j, quadrato-jugal ; na, nasal; ff, parieto frontal; 

 ex, ex-occipital ;.////, foramen magnum ; pro, pro-otic ; sq, squamosal ; s/>. ct, 

 sphenethmoid ; par, parasphenoid ; //, palatine ; vo, vomer ; pt%, pterygoid ; 

 av, atlas vertebra ; c, centrum ; ar, neural arch ; svg, zygapophysis ; trv, trans- 

 verse process ; u,-, urostyle ; //, body of the hyoid ; Ha. anterior cornu ; //>, 

 posterior cornu of the hyoid. 



