84 REPTILES. 



direct contact with the frontals ; upper labials not touching the 

 orbit, separated from it by suborbitals. Ground colour yellowish 

 brown, with a dorsal and a lateral series of large dark blotches ; 

 beneath with oblong black spots. 



a. Adult. Buenos Ayres. From M. Parzudaki's Collection. 



b. Adult. South America. From the Haslar Collection. 



c. Adult. South America. 



5. Heterodon madagascariensis. 



Dum. 4' Bihr. p. TiQ. pi. 69. 



Scales smooth ; azygos shield behind the rostral none ; two of 

 the upper labials coming into the orbit. Brown, sometimes on 

 the sides with broad, black, obhque, confluent cross bands. 



a. Adult. Madagascar. From the Leyden Museum. (Uniform.) 



Fam. IV. COLUBRID^. 



Body moderate, sometimes elongate, in the last genera some- 

 times slender. Tail generally of moderate length, not distinct 

 from trunk, tapering. Head moderate, with flat crown, rather 

 distinct from neck, quadrangular, with moderate rounded, some- 

 times pointed muzzle. Shields of head exceptionally irregular. 

 Cleft of mouth deep. Nostril lateral. Eye moderate, some- 

 times large, with round pupil. Loreal shield never wanting. 

 Nostril between two nasals. Scales ovoid, of nearly equal size 

 on the back, moderately imbricate. Subcaudals two-rowed. 

 Teeth never grooved, generally of equal length ; in one genus 

 posterior maxillary tooth longest; in another, maxillar}' teeth 

 becoming gradually longer behind. 



Coluber, Schleg. Ess. ii. p. 125. Plagiodontiens, Corypho- 

 dontiens, Isodontiens pt., Periops, Zamenis (Diacranteriens), 

 Dum. 4" Bibr. 



Synopsis of the Genera. 



1. Rhinechis. Rostral shield much protruding, rounded, 



higher than broad, far produced backwards, sharply pointed 

 behind. Scales smooth. South Europe. 



2. PiTUOPHis. Rostral shield as in Rhinechis. Scales keeled. 



North America. 



3. Coluber. Rostral moderate. Body with rounded back, 



generally moderate ; one anterior, two posterior oculars. 

 Teeth equal. Europe ; Asia ; North America. 



