8/4 ANATOMY AND DEVELOPMENT 



of the legs. This band is more prominent in the lighter coloured 

 vaiieties than in the dark, and is especially conspicuous in large 

 individuals. It is due to a diminution in the green pigment, and 

 an increase in the brown. 



There is a dark line running down the middle of the dorsal 

 surface, in the middle of which is a fine whitish line. 



The ventral surface is almost entirely free from the green 

 pigment, but possesses a certain amount of light brown. This 

 brown pigment is more conspicuous and of a darker shade on 

 the spinous pads of the foot. 



In parts of the body where the pigment is scarce, it is seen 

 to be confined to the papillae. This is especially evident round 

 the mouth, where the sparse green pigment is entirely confined 

 to the papillae. 



In some specimens a number of white papillae, or perhaps 

 light brown, are scattered over the dorsal surface ; and some- 

 times there is a scattering of green papillae all over the ventral 

 surface. These two peculiarities are more especially noticeable 

 in small specimens. 



Ridges and Papilla of the Skin. The skin is thrown into 

 a number of transverse ridges, along which the primary wart- 

 like papillae are placed. 



The papillae, which are found everywhere, are specially de- 

 veloped on the dorsal surface, less so on the ventral. The 

 papillae round the lips differ from the remaining papillae of the 

 ventral surface in containing a green pigment. Each papilla 

 bears at its extremity a well-marked spine. 



The ridges of the skin are not continued across the dorsal 

 middle line, being interrupted by the whitish line already 

 mentioned. Those which lie in the same transverse line as 

 the legs are not continued on to the latter, but stop at the 

 junction of the latter with the body. All the others pass round 

 to the ventral surface and are continued across the middle line ; 

 they do not, however, become continuous with the ridges of the 

 other side, but passing between them gradually thin off and 

 vanish. 



The ridges on the legs are directed transversely to their 

 long axes, i.e. are at right angles to the ridges of the rest of the 

 body. 



