42 LIZARDS OF THE PHILIPPINE ISLANDS 



and pirrit (Moro) ; the larger ones are known as chacon (Spa- 

 nish-Tagalog) ti-ki (Leyte Visayan), ti-kd (Ilocano) and tok-ko 

 (Tagalog). 



The call of the smaller species is a series of quickly repeated 

 clicks or chirps. When fighting they utter a long growling note 

 in a much lower pitch, which can be heard at a distance of several 

 meters. The call of Gekko gecko is preceded by several short, 

 rapid, guttural notes. The call is ''tok-ko," repeated slowly, 

 seven or eight times, the ultimate note somewhat prolonged. 



The tails of the geckos are very fragile. When one is broken 

 off, a cartilaginous process is developed from the centrum of the 

 last remaining vertebra, and muscles, skin, and scales appear on 

 this process. Regeneration continues until the tail regains 

 nearly its normal length. The new tail readily breaks, and a 

 new growth takes place. Specimens showing three or four 

 separate growths are not uncommon. Occasionally a double or 

 bifid tail is produced. 



In the normal tail of many species the various vertebrse of the 

 tail are indicated by annulations due to the arrangement of the 

 scales. In the regenerated tail these annulations are usually 

 wanting, and the character of the scales is different. 



Most of the geckos are lowland species. None was found by 

 me in the vicinity of Baguio, which has an elevation of about 

 1,400 meters; and Lepidodactylus planicaudus Stejneger from 

 less than 2,000 meters on Mount Apo, Mindanao, has the highest 

 range of any Philippine gecko. 



Key to the Philippine genera of the Gekkonidse. 



a\ Digits slightly dilated at base, two or three distal joints narrow, 

 compressed, and angularly bent; all digjts clawed; claw between 

 two scales, a small superior and a large lateroinferior. 



Gymnodactylus Spix (p. 43). 

 a^ Digits dilated; a single distal phalanx long and compressed. 



b\ The free distal joint long, rising from within the extremity of the 

 distal expansion; digits with transverse lamellae below, either in 

 double or single rows. 

 c\ Infradigital plates in a double series. 



cf. Inner digit with a compressed clawed phalanx; dorsal scales 

 granular or with tubercles intermixed; no lateral flaplike 



expansion of skin Hemidactylus Oken (p. 52). 



6?. Inner digit with clawed distal phalanx; a lateral flaplike expan- 

 sion of skin; scales granular; no tubercles. 



Coiymbotus Fitzinger (p. 59). 

 c\ Infradigital plates divided by a median line; inner digits without 

 distal phalanx or claw; digits strongly dilated. 



Peropus Wiegmann (p. 62). 



