224 Zoological Society : — 



prominent and turned up. Both the head and the lower jaw are 

 deeper than in C. vulgaris and C. leptorhynchus. (See fig. 4, which 

 represents the head of C.frontatus seen in profile, and figs. 5 and 6, 

 which respectively represent the profiles of the head of C. vulgaris 

 and C. leptorhynchus.) The disposition of the scuta or plates along 



Fig. 6. 



the nose or muzzle is different in each species. Fig. 7 shows them 

 in C. frontatus ; fig. 8, in C. vulgaris ; and fig. 9, in C. leptorhyn- 

 chus. It will be seen that the arrangement in C. frontatus is much 

 nearer that in C. vulgaris than that in C. leptorhynchus, v/hich. is upon 



Fig- 7. 



a totally different plan, the middle space in it being free from scuta, 

 soft, and smooth, with transverse wrinkles or lines, while in the other 

 two the space is covered with scuta, those in the middle being trans- 

 verse. The commencement of these transverse scuta between the 

 eyes is also different. 



