ARKIV FOR ZOOLOGI. 



BAND 1. 



On the adaptations to a niolluscivorous diet in 

 Varanus niloticus. 



by 

 Dr EINAR LÖNNBERG. 



With 5 figures in the text. 



Received 11 March 1903. 

 Communicated by F. A. Smitt and Hj. Théel. 



It is a well-known fact tkat tlie Varanus-lizarås are 

 very rapacious aniraals, and tliat they prey upon almost all 

 kinds of living beings tliat they can overpower, from in- 

 sects to vertebrates, such as lizards, rodents etc. The sharp- 

 ly pointed and compressed* teeth of most species belonging 

 to this genus are tlras admirably well suited to act as fångs 

 for catching and holding the prey, the more so as they are 

 also somewhat recurved, and to a certain degree, resemble 

 the teeth of some snakes. This recurved or hooked shape 

 also facilitates the act of swallowing the prey as the latter 

 can slip backward towards the gullet but not forward. The 

 prey is swallowed in its entire state, as in most reptiles, and 

 not masticated. I have, for instance, dissected out of the 

 stomach of a Varanus salvator a whole and very little lace- 

 rated Galotes. It is also evident from the shape of the teeth 

 that they, although splendid as fångs, are not at all adapted 

 for any chewing action. All species of Varanus are, how- 

 ever, not alike in this respect. Through my friend Mr. Gunnar 



* The lateral tompression means, at the same tiiue as material is saved. 

 a strengthening in the anteroposterior direction in which the strongest pull 

 affects the teeth when an animal is canght and tries to slip away. 



Arkiv för zoologi Bd. 1. 6 



