52 INTRODUCTION 



No snake shows any rudiments of the pectoral 

 arch, but remains of the pelvic are found in the 

 Typhlopidce, the Glauconiidce, the Boidcz, and the 

 I ly slides. In the first these vestiges are reduced to a 

 single bone (ilium ?) on each side ; in the second they 

 consist of ilium, pubis, and ischium, the latter form- 

 ing a ventral symphysis, and a rudimentary femur ; 

 whilst in the third there is a long ilium, attached to 

 the lower branch of the first bifurcate transverse pro- 

 cess of the lumbar vertebrae, bearing three short 

 bones, the longest of which, regarded as the femur, 

 terminates in a claw-like spur which, in males at 

 least, usually appears externally on each side of the 

 vent. 



