WHEEL-BEARERS. 



249 



blance to the head of a rabbit, the antenna representing 

 the ears. In front, and just below this head-like proboscis, 

 is a double swelling, containing the rotatory organs, which 

 are small and seldom unfolded. The eyes are deep black ; 

 probably, as in the last example, a red of great intensity. 

 When the head is withdrawn, the 

 integument is very clearly seen to 

 be turned inwards. The body con- 

 sists of one long cylindrical tube, 

 which receives three or four short 

 joints to complete the abdomen ; at 

 the dorsal point of the extremity of 

 the last of these is the cloaca ; at 

 this part the diameter is already 

 very much attenuated ; but there 

 are eight or nine more joints which 

 constitute the foot, and these are of 

 extreme slenderness. Towards the 

 extremity, two processes are given 

 off behind, each consisting of a club- 

 shaped piece, with a slender bristle 

 at the tip. The foot terminates in three long, slender, 

 cylindrical, divergent toes, which are flexible, and com- 

 monly bent outward ; they are equal in thickness, and 

 truncate. These are often retracted in various degrees, 

 even when the foot is otherwise extended. 



Owing to the slenderness of the body, the viscera are 

 greatly elongated. The mastax, as usual in this family, 

 consists of two hemispheres (each bearing two teeth, set 

 transversely, but converging to the centre) ; it is situated 

 at a considerable distance from the wheels, and is reached 

 by a long buccal funnel. The digestive canal is a long 

 sac, apparently undivided ; it originates directly from the 

 mastax, with, I think, two small basal glands; its pos- 

 terior extremity becomes gradually tapered to the cloaca. 

 In the specimen we are examining, a small quantity of 



TRIPOD WHEEL-BEARER. 



