DEFINITION AND CLASSIFICATION 5 



2. No vestiges of pelvis ; supratemporal absent 



5. Uropeltid,e. 



B. Coronoid absent ; supratemporal present. 



1. Maxillary horizontal ; pterygoids reaching 



quadrate or mandible. 



Nasals in contact with prefrontals 



6. Xenopeltid.e. 

 N asals not in contact with prefrontals 



7. COLUBRID.E. 



Three series: A. Aglypha (subfamilies: Acrochor- 

 dince, Colubrince, Dasypeltince) ; B. Opisthoglypha 

 (Homalopsincz, Dipsadomorphincz, Elachistodontince) ; 



C. Proteroglypha {Hydrophiince, Elapincz). 



2. Maxillary horizontal, converging posteriorly 



towards palatine ; pterygoid not reaching 

 quadrate or mandible 8. Amblycephalid.e. 



3. Maxillary vertically erectile perpendicularly to 



transverse bone; pterygoid reaching quad- 

 rate or mandible 9. Viperid^e. 



(Subfamilies : Viperince, Crotalince.) 



The technical terms employed in the above 

 synopsis will be found explained and illustrated by 

 figures in the chapter on the Skeleton. 



No serial arrangement can express the affinities 

 of the various groups as conceived by the classifi- 

 cator ; a diagram therefore follows to show the 

 author's views as to their interrelationships, and 

 possibly their phylogeny. Leaving aside the 

 Typhlopidae and Glauconiidae, which should be re- 



