CROCODILIDAE 



463 



It occurs in every pool and river in great numbers, especially 

 upon the sandbanks of the Betsiboka Eiver, v^rhere one may see 

 more than one hundred within one hour's paddling down stream. 

 The largest specimen measured by Yoeltzkow was 1 3 feet long ; 

 the largest in the National Collection is a little less than 15 

 feet. 



The crocodiles are caught in various ways. Tlie simplest 

 apparatus consists of two pointed sticks, which are fastened cross- 

 wise within the bait to which is attached a rope, and this is 

 made fast on the bank of the river or lake. The animal, when 

 it has once swallowed this spiked bait, keeps its jaws firmly 

 closed, so that it can be dragged' out of the water. Another 

 method is more reliable. A long and strong rope is made into 

 an easily slipping noose, with an opening of about 18 inches. 

 The bait is attached to the upper part of the nOose, while the 

 lower portion is kept open by a springy branch, the whole 

 thing being so balanced that it will float upright. When a 

 crocodile seizes the bait, which it does with a side jerk of the 

 head, the branch falls out of the noose and the latter closes 

 around the upper or lower jaw. 



These crocodiles dig long subterranean passages of 30 to 40 

 feet in length ; the passage opens in the bank below the level of 

 the water, and gradually ascending ends in a somewhat wider 

 compartment, which allows the creature to turn round. Two or 

 three air-holes are pierced through the ceiling of the burrow, in 

 which bones and other remains of food are often found, so that 

 the natives' belief, that the crocodiles retire into these chambers 

 in order to devour their prey in undisturbed secrecy, appears 

 very probable. When ■ suddenly disturbed or frightened they 

 take to these lairs, and since their position is clearly marked by 

 the air-holes, the natives block the passage and then dig the 

 animal out from above. 



Eggs are laid, in Madagascar, from the end of August to the 

 end of September ; the number of one set varies. from twenty to 

 thirty. They are deposited in a nest. This is in the ground, 

 mostly in white sand, and consists of a hollow 18 inches to 

 2 feet deep. The walls are rather vertical, but near the bottom 

 they are undermined, and here the eggs are placed. The centre 

 of the pit being somewhat higher, the eggs roll by themselves 

 into the undermined peripheral region. The laying takes place 



