38 LIZARDS OF THE PHILIPPINE ISLANDS 



Palawan, but the genus appears to be represented with equal 

 frequency elsewhere in the Islands. No closely related genus 

 is known in any adjacent territory. The absence of this genus 

 from northern Borneo (if it is indeed absent) would suggest 

 that it is of comparatively recent development. There are no 

 less than three species of the genus in the Sulu region, which 

 lies nearest Borneo. If our theories of the migration of species 

 merits serious consideration, some of these species should 

 certainly have reached the northern Borneo coast while the 

 transfer of species represented by • the twenty-one common 

 genera mentioned above was being made, unless they are indeed 

 a later development. This theory, how^ever, is hardly substan- 

 tiated by the wide distribution in the Philippines. 



Luperosaurus has three known species; one on Calayan, Babu- 

 yan Islands, in the extreme northern part of the group, and a 

 second on Jolo Island, in the extreme southern part of the 

 Archipelago. The exact type locality of the third is unknown. 

 All of these species are known by only the types and cotypes. 

 Owing to the apparent rarity of the lizards of this genus they 

 may have easily remained undiscovered in Borneo and neigh- 

 boring islands. 



Pseudogekko appears to have its nearest relative in the genus 

 Thecadactylus, which occurs in New Guinea and certain adjacent 

 islands. It is extremely rare, only three specimens, of the single 

 known species, being known. 



CLASSIFICATION OF THE LIZARDS 



Several systems for the classification of the lizards have been 

 offered by various authors in recent years. They vary material- 

 ly, chiefly in the relative importance of the higher groups. Bou- 

 lenger's Catalogue,* since its publication, in 1885-1887, has been 

 the standard work on this group of animals ; just as the Erpeto- 

 logie General, of Dumeril and Bibron, had been prior to that time. 

 Boulenger's system of classification of the living forms is as 

 follows : 



Order. Squamata.f 

 Suborder I. Ophidia (snakes). 

 (Numerous families.) 



* Boulenger, G. A., Catalogue of the Lizards in the British Museum 

 (Natural History) 1 (1885), 2 (1886), 3 (1887). ' 



t See also Boulenger, Fauna Brit. India (1890) 52; and Ann. & Mag. 

 Nat. Hist. V 14 (1884) 120. 



