PHILOSOPHICAL TEANSACTIONS. 



I. On the Structure and Develojynient of the Shdl in the Batrachia. — Part III. 

 By William Kitchen Pakker, F.R.S. 



Received AprU 29,— Read May 27, 1880. 



[Plates 1-44.] 



INTRODUCTION. 



• 



My first attempt at working out the morphology of the Batrachian skull (Phil. Trans., 

 1871), instead of satisfying my mind, only served to increase tenfold the desire to 

 know the meaning of the mysterious changes undergone by that pai't — the main part 

 — of the organisation of the Frog. 



Since then no opportunity has been lost of laying up in store I'resh and fresh 

 materials for further work in this field of research. Moreover, an additional strip of 

 ground has since then been cleared and cultivated (Phil. Trans., 1876) ; in that second 

 essay I was greatly helped by Professor Huxley, who showed me what was wrong in 

 the first attempt, and also cut througli some of the thickest and thorniest parts of this 

 tangled subject. 



I am also indebted to him for niateridls, and also to Professor A. Aga.ssiz, and 

 Mr. Garman (of Harvard University, U.S.) ; also to Pi'ofessor Rupert Jones, Dr. 

 GiJNTHER, Professor W. H. Flower, Dr. Murie, Dr. Dobson, Mr. T. J. Moore (of 

 Liverpool), W. Fercjuson, Esq. (Ceylon), James Wood-Mason, Esq. (Calcutta), 

 Alfred C. Haddon, Esq., and George Dines, Esip 



Primarily, the aim of this extended research into tlie moaning of the .skull iu one 

 " Order," or main group, is to get light upon the great cranial problem. A second use 

 will be to rectify the classification of the group itself 



To make a systematic classification of these metamorphous animals upon such 



MDCCCLXXXI. B 



