WHEEL-BEAEEES. 287 



complete tlie al)doinen ; at the dorsal asj)ect of the ex 

 tremitj of the last of these is the cloaca ; at this point 

 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 bodv, the viscera 

 are greatly elongated. The mastax, as nsual in this 

 family, consists of two hemispheres (each bearing two 

 teeth, set transversely, bnt 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 origi- 

 nates directly from the mastax, with, I think, two small 

 basal glands ; its posterior extremity becomes grad- 

 ually tapered to the cloaca. In the sf)ecimen we are 

 examining, a small quantity of fsecal matter of a yel- 

 lowish-brown colour is collected in two small masses, 

 near the extremity. Along the ventral aspect runs 

 the ovary, which in this specimen contains two long 

 oval eggs in advanced development ; from their trans- 

 parent brightness, I suspect the young are produced 

 before birth. I think I can detect a contractile blad- 

 der, but am not certain. 



The dorsal region of the trunk is marked with 

 strong rugged lines running longitudinally ; these look 

 like corrugations of the integument, but I incline to 



