360 



LOWER VERTEBRATES. 



possibly be regarded as a northern variety of the more tropical £oa constrictor, 

 though the scales of the head are rather large. The general color is brownish, with a 

 dorsal series of quadrangular brown spots, which is separated from the smaller spots 

 of the flanks by a pair of light lateral lines. i>. constrictor, though properly an inhabi- 

 tant of Brazil, is represented in Central America by a variety, isthmica. Along the 

 back is a series of transverse brown bands, each connected with the marks of the 

 flanks by a latero-posterior isthmus, and along each side of the belly is a series of more 





t^i^"^ 



Fig. 212.— Boa ccmstrictor. 



or less broken, irregular spots of a black color. £. mexicana is allied to £. im2}erator. 

 £. constrictor, proper, inhabits the more tropical portions of South America, though 

 travelers from all parts, of the world have almost invariably described large serpents 

 which have come under their notice as ' Boa-constrictors,' rendering it extremely 

 diflicult to determine acurately what species they are describing, and bringing the 

 name to so general a use that it has almost lost tlie primary significance given it by 

 its original propounder, Linne. 



