256 Records of the Indian Museum. [Voi,. Ill, 



extends along the Himalayas into the drier and colder parts of 

 Nepal. Ch. hlanjordiana is the onl}'- species of Charasia I have 

 been able to observe alive. In its habits it closely resembles 

 Agniiia tuherciilata , being usuall)^ seen on rocks but occasionally 

 entering hmnan dwellings and running about on the walls. The 

 male, in April and Ma}^ has the head and fore-quarters of a 

 brilliant red colour, and displays his magnificence to the female, 

 which remains concealed, by slowly walking along in some conspicu- 

 ous position, alternatel}^ raising and nodding his head in a very 

 solemn manner. The exact tint of the brilliant parts changes as he 

 does so. Both sexes possess considerable powers of temporary 

 colour change, which seem to be called into play mainh^ b}^ the 

 amount of reflected light that reaches the integument. The 

 changes do not always assist in concealing the animal. I have 

 seen a temporarily pale individual resting most conspicuous on a 

 red mud wall, and another on a black rock from the surface of 

 which the sun was reflected. On the other hand, other individuals 

 ofi similar rocks and walls in the shade were much darker and less 

 conspicuous. The fact seems to be that the number of different 

 colours that can be brought into play by contraction or expansion 

 of the pigment cells of this species is a very limited one. Strong 

 reflected light causes certain of the pigment cells to contract, but 

 does not expose others. The lizard, therefore, can become paler 

 or darker, but cannot change its actual coloration to any great 

 extent. Some of the pigment cells, however, are probabl}^ non-con- 

 tractile, for the symmetrical markings never disappear but become 

 more conspicuous as the general tone becomes paler. Specimens 

 in spirit from Travancore are much blacker {i.e., less brown) than 

 specimens from Paresnath, on which the rocks are not so black as 

 those of the Western Ghats of Travancore. It is probable, there- 

 fore, that in Charasia as in Hemidactylus, environment has more 

 than a transitory effect on coloration. 



10. Mahuia carinata. 



Common in open country as well as in jungle at the base of 

 the hills ; often seen in pairs sunning itself on fallen tree-trunks or 

 rocks. 



II. Lygosoma dussumieri. 



Perhaps the commonest skink in the plains of Travancore, 

 both in open country and in jungle at the base of the hills. The 

 form I described [Journ. Asiat. Soc. Bengal, 1905, p. 145) as '' var. 

 concolor " is the typical female, which is not only larger and 

 stouter than the male, but much more soberly coloured and retiring 

 in its habits. The tail in the male is bright red, while in the 

 female it is brownish ; the white lines running along each side of 

 the back and sides in the former sex are obsolete or obsolescent in 

 the female ; and the same is the case as regards the dark spots on 

 the dorsal surface. 



