140 ANOTHER VISIT TO THE ANDAMANS 



period of spring-tides, until at last the creek is filled 

 up with their remains, mingled with fallen leaves, etc., 

 from the overhanging jungle. If, on the other hand, 

 the creek should have become connected with a channel 

 of rain water — as does sometimes occur on the Cocos — 

 then some of the marine animals periodically thrown 

 into it by the spring-tides may live, even should the 

 periodic communication with the sea altogether cease, 

 and may, if the fresh water be of sufficient extent and 

 volume, gradually colonise it, and flourish in it even 

 after the parent stock has become extinct in the sea. 



Among the animals that we noticed in the jungle, 

 there were, in addition to those observed the year 

 before, a land-crab {Geograpsus grayi) which we had 

 encountered in the Laccadives, an Agamoid lizard 

 {Gonyocephalus subcristahts), peculiar to the Andaman- 

 Nicobar chain, and a beautiful little tree-gecko {Phel- 

 suma andamanense), found only in the Andaman group. 

 This little gecko is one of the most brilliant lizards 

 in existence : above, it is of the most vivid emerald- 

 green, flecked here and there with orange-red ; below, 

 it fades to yellow, the throat being of a particularly 

 bright hue."^ Peculiar interest attaches to this little 

 denizen of the jungles, because its known congeners 

 are confined to Madagascar and the neighbouring 



* Like most lizards, Phelsuma andamanense can change its 

 colour on occasion ; for instance, on a dark background, or in bad 

 light, it turns a dingy brown, and its orange markings become 

 dim and obscure. 



