162 THE GENUS PERIPATUS. 



has one main tooth (fig. 28)^ at the base of which is a small 

 tooth. This accessory tooth is found on the outer blade in 

 all South African species. Posteriorly, the behaviour of the 

 two blades is very different. The epithelial ridge bearing the 

 outer blade is continued back for a short distance behind the 

 blade, but the cuticle covering it becomes very thin, and it 

 forms a simple epithelial ridge placed parallel to the inner 

 blade. The cuticle covering the epithelial ridge of the inner 

 blade is, on the contrary, prolonged behind the blade itself as 

 a thick rod, which, penetrating backwards along a deep pocket 

 of the buccal epithelium, behind the main part of the buccal 

 cavity for the whole length of the pharynx, forms a very 

 powerful lever, on which a great part of the muscles connected 

 with the jaws find their insertion. 



The Ambulatory Appendages.— The claw-bearing legs 



are in seventeen pairs, and with the exception of the fourth 

 and fifth pairs in both sexes, and the last in the male, they all 

 resemble each other fairly closely. A typical appendage will 

 be first described and the small variations found in the appen- 

 dages just mentioned will then be pointed out. Each consists 

 of two main divisions, a large proximal portion the leg, and 

 a narrow dorsal, claw-bearing portion, the foot. 



The leg (fig. 2) has the form of a truncated cone, the broad 

 end of which is attached to the ventro-lateral body wall, of 

 which it appears to be, and is, a prolongation. It is marked by 

 a number of rings of primary papillse, placed transversely to 

 the long axis of the leg, the dorsal of which contain a green 

 and the ventral a brown pigment. These rings of papillae at the 

 attachment of the leg, gradually change their direction and 

 merge into the body rings. At the narrow end of the cone 

 there aie three ventrally placed pads, in which the brown 

 pigment is dark, and which are covered by a number of spines 

 precisely resembling the spines of the primary papillae. These 

 spinous pads are continued dorsally, each into a ring of 

 papillae. 



The papillae of the ventral row next the proximal of these 

 spinous pads are intermediate in character between the primary 



