Boa- Constrictors of British Guiana. 307 



exceptional. They are found much more frequently in the 

 forest districts than in the open lands. 



The three remaining boas — species of Corallus — are very 

 sharply marked off from the preceding forms by the deep 

 labial pits, which are distinguishable at a glance. The most 

 striking of the three is the green tree-boa {C. caninum)^ 

 which, as in the case of young anacondas, frequents the low- 

 bushy growths by the riverside, on which, owing to their 

 colour, it is very difficult to detect them. 



The prevailing green colour of the back is varied by a series 

 of white mosaic mottlings arranged transverse to the body, 

 giving to the species a very characteristic appearance. In 

 young specimens, at any rate, the colour seems to be very 

 variable, the green often giving place to bright red, the white 

 mosaic being the same. In the writer's experience no small 

 green specimens have ever been met with in the colony, while 

 young red ones are fairly common. On the other hand, no 

 large red individuals have ever been seen, only the green 

 ones. In preserved specimens, in which the tints have been 

 more or less lost, the red and green examples are almost 

 indistinguishable ; but while the red colour is quickly 

 destroyed and the specimen becomes quite pale, the green 

 lasts quite brightly for a very long time, more especially in 

 spirits. In life, however, the difference in colour is most 

 remarkable. 



Throughout the colony generally this form is often con- 

 founded with the green labarria, the enlarged anterior 

 maxillary teeth being mistaken by the ignorant for poison- 

 fangs. The structural differences, however, are very great, 

 while the very noticeable white markings along the back will 

 at once distinguish this non-venomous species from the 

 Crotaline form. 



Among the Carib tribes this snake is known by the name 

 Wy-o-pomoi. It is termed by them a " bad " snake, and 

 possibly this refers to the severe gashes which it can inflict 

 with its long teeth. 



The two remaining species of Corallus very closely 

 resemble each other in their general form. They are elon- 

 gated and slender, much more so than the other boas, and the 

 neck is sharply constricted, giving a triangular shape to the 

 head. The body is marked by alternating series of trans- 

 versely elongated dark brown or purplish blotches, often 

 enclosing paler spaces ; and on each side of the head, behind 

 the eye, is an oblique dark brown streak. 



In the commoner species {C. hortulanum) the ground- 

 colour is a pale brownish grey, and the head is marked by a 



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