THE VARIATION EXHIBITED BY ANCISTRODON HALYS (PALLAS) 
A PIT-VIPER INHABITING THE FAR EAST 
BY 
JOSEPH C. THOMPSON 
SURGEON. UNITED STATES NAVY 
CONTENTS PAGE 
Introduction _____ 136356355 See aE eee 6l 
Variation in Number of Vertebrae  -. ---- 6 63 
Variation in Sum of Gastrosteges and Urosteges <a = 64 
Variation in Gastrosteges -.-. __-__-_- | eee 64 
Variation in Urosteges =e SaaS ages 65 
Variation in Seale Rows. .___ =e oe SSeS Oe _65 
Central Asia =ae2 sae : SiS 6 A See 69 
Ussuri Province 2 ae Bonte cece ce eee se =e 55 8) 
Greate einer eenrnperen EO) ns ee JSS5 69 
(Chit 25-2 se 69 
Napanee ee aan ee nn 2 69 
Variation in Physiognomy : : eee 70 
Variation in Prefrontals im ts pies ati =e = : 70 
Variation in Frontals ___- : Srotels ees os SS See ae Se 70 
Variation in Postoculars ____ SSS Sop SSeS 7A 
Variation in Temporals = = bee ee oe all 
Variation in Supralabials Jae es 22 foeftsteossesee 72 
Variation in Infralabials —___ = : : see! 
Summary of Variations eta aNee aia ae 76} 
Position of Viscera___ = =/65) 
Alleged Occurrence in ee Ie Chon Tends j : = ; ae : =f) 
