1901.] LIZARDS OF THE " SKEAT EXPEDITION." 303 



nostrils directed laterally, the other with the nostrils directed 

 vertically upwards. The former group has a wide range. On 

 the mainland, D. maculatus ranges from Yunnan to Singapore ; in 

 Hainan it is replaced by the closely allied D. ivhiteheadi. Isext 

 come two species common to the Malay Peninsula and the three 

 great Malay Islands, A'iz. D. volans and D.Jimbriatus. D. jnmctatus 

 is known from Borneo and the Peninsula, and there are three 

 species confined to Borneo : these are D. cornutus, D. rostratus, 

 and D. cnstatellus. Eastwards, D. lineatus has been recorded from 

 the Moluccas and doubtfully from Java. Eour species are known 

 to inhabit Celebes : one of these, D. reticulatus, occurs also in the 

 Philippines, which have also six or seven ' precinctive ' species. 

 Lastly, D. lualkeri and D. iimorensis are found in Timor. On the 

 other hand, the second group does not extend farther east than Java. 

 It may conveniently be divided into two sub-gi'oups : in one the 

 gular pouch of the males is covered with very lai'ge scales, in the 

 second the scales on the pouch are not enlarged. 



The first sub-group contains four species, these ai-e : — 



B. hlanfordi, from Tenasserim to Perak (Larut Hills). 

 D. tceniopterus, Tenasserim and Siam. 

 I), formosus, Peraii and Penan g. 

 D. ohsGurus, Borneo. 



I), formosus is intermediate in structui-e between the first two 

 species. 



Of the second sub-group, D. dussumieri is found in India; all 

 the others are from Borneo, but some range into Java, Sumatra, 

 aud the Malay Peninsula : — 



Borneo. Java. Sumatra. Peninsula. 



D. w.a,viinus, 

 D. affinis. 



D. quinqtiefasciatus. D. quinquefasciatus, 



I), micropterus. 



D. hcematopogon. D. Juematopogon. D. luematopogon. 



D. melcmopjogon. D. melanopogon. 



On the whole the Peninsula comes nearer to Borneo than do any 

 of the other neighbouring countries ; the other Agamoid lizards 

 support this view strongly. The genus Aplianiotis is common 

 to Borneo and the Peninsula, and not found in Java or Sumati-a. 

 The last-named island, on the other hand, has the precinctive 

 genus Plioxoplirys, and one species of the genus CopJiotis, of which 

 the other species is found in Ceylon, and belongs to a small group 

 of three genera with processes on the snout otherwise peculiar to 

 Ceylon. Java has the precinctive genus Harpesaurus, and is 

 inhabited by Loplmrus amboinensis, an eastern form belonging to 

 that group of j^gamoids furnished with femoral pores. 



There remain for consideration three large genera widely 

 distributed in the Oriental region. One of these, AcantJiosaura, is 

 entirely continental and reaches its southern limit in the Peninsula. 

 The second, Gonyocep)halus, is chiefly found in the archipelago, 

 as far east as N. Guinea ; this genus is represented in the 



