118 ON HELODKRMA HORRIDUM AND H. STJSPECTUM. [Jail. 20, 



The probable affinities and phylogeny of these five groups are 

 expressed by the following diagram : — 



RJiipiofflossa. . 



Pythonomorpka. LocertiUa. 



Dolichosauria. 

 Fig. 6. 



Opiiidia. 



i n 





A, 



C. 



B. 



D. 



A. Hind limb of Bolichosannts lednensis (after Komhuber) ; B. of Edcsto- 

 saurus (after Marsli) ; C. of Varanus ; D. of Chmiueleon. 



These figures illustrate the principal modifications of structure of 

 the limbs in the four Suborders in which they are developed. 



