Boa- Constrictors of British Guiana. 297 



In size this water-boa seems to exceed all other snakes, and 

 it would appear to be more deserving of the ancient name 

 Anaconda than the Eastern forms to which it was first applied. 

 In fact, it may be said that the name is almost limited nowa- 

 days to this tropical American species. The length is known 

 to reach quite 37 feet, but it is said that much larger speci- 

 mens have been taken. On this pcint, however, it is hardly 

 safe to express an opinion, since unless definite measurements 

 are made, the estimate of size can be of little value. 



A case in point, which would suggest caution in accepting 

 the great lengths ascribed to certain animals, may be quoted 

 from the writer's experience as regards the large Black Alli- 

 gator locally known as Caiman {Alligator niger). The length 

 of tliis form is given by various travellers in the colony, as, 

 for instance, by both Brown and Schomburgk, as from 20 to 

 25 feet, Waterton even recording 30 feet ; but there is no 

 statement of actual measurement. In the writer's experience 

 the largest forms of this species, taken in the very districts 

 referred to by the forementioned travellers, hardly exceeded 

 14 feet, though when seen in the water they appeared to be 

 considerably larger. A similar example may be found in the 

 great Arapaima fisli {Arapaima gigas), which is recorded as 

 from 16 to 18 feet in length, while in reality they hardly 

 attain to more than half that size. Actual measurement is 

 requisite in all such cases. 



tSkins of the wafer- boa of from 18 to 25 feet in length are 

 frequently obtained, and in the sheltered swamps and along 

 the creeks in tlie recesses of the forests it may well be that 

 considerably larger animals would be met with. The 

 following experience along the higher Essequibo River tends 

 to support this. In 1894, while passing by a wide outgropv'th 

 of closely matted grass from the swampy bank, the boat 

 disturbed an enormous snake, of which the head, neck, and 

 part of the body were clearly seen at a distance of certainly 

 not more than 5 feet. It was noticeable that the head was 

 considerably more than twice as large as that of one of about 

 20 feet, and this seems to indicate a snake of very large pro- 

 portions. 1 he unlbrtunate part of the matter is that snakes 

 of very great size are most likely to be seen in places where 

 it is out of the question to secure them, as it happened in this 

 particular case. 



The body of the water-boas is thick in proportion to its 

 length and cylindrical, owing to the strongly developed dorsal 

 muscles from which they derive their great strength. The 

 males, as a rule, are more elongated, and the females thicker 

 towards the end ot the body. In this species, as in the other 



