VIII 



of the upper eyelid, its depth is the vertical distance between 

 canthus rostralis and mouth, measured at the anterior border 

 of the upper eyelid. The luidtli of the interorbital space is 

 the smallest distance between the upper eyelids. The size of 

 the tympanum is measured along its greatest diameter. 



In the tadpoles the ividtli of the body is taken in its broadest 

 part; with length of the body is meant the distance from the 

 tip of the snout to the point of origin of the hind limbs; 

 the length of the tail is measured from this point to its tip, 

 its depth is taken at its highest point, both crests included. 

 The number of series of horny teeth is indicated by a for- 

 mula, f. i. 3 '3/' 2' signifies: four series in the upper, three 

 in the lower lip, the three lower (inner) ones of upper lip 

 and the upper (inner) one of lower lip each being divided 

 into two portions by a median interruption. 



I wish to direct the attention of collectors on the fact, 

 that only very few tadpoles of Indo-Australian Anura are 

 known at present. In collecting tadpoles, however, it is necessary 

 (when it is impossible to rear them) to collect material of young 

 and full-grown frogs at the same locality; otherwise the tad- 

 poles usually cannot be determined. The best preservation 

 fluid for tadpoles is formol. 



I have to express my thanks to Prof. Max Weber for his 

 valuable assistance in many points. I am much indebted also to : 

 Mr. Th. Barbour, Dr. G. A. Boulenger, Prof. L. Dollo, 

 Mr. C. BoDEN Kloss, Prof. L. Roule, Dr. J. Roux, Mr. Malc. 

 Smith, Dr. Th. Vogt, Prof. F. Werner for useful infor- 

 mations and the sending of specimens for examination. 



Leiden, July 1923. P. N. VAN Kampen. 



