WHEEL-BEARERS. 



243 



the lorica unusually thick ; this is, however, an optical 

 illusion, dependent on its dilatation into those angular 

 wings already noticed. The cavity penetrates into them ; 

 for in one of these specimens I see those curious twisted 

 threads that are believed to be connected with respiration, 

 within the lateral wings. The stomachs are generally full 

 of green and brown food, but they will not imbibe car- 

 mine. 



SKELETON WHEBL-BKARER. 



Let us look, however, a moment longer at the singular 

 foot. Between the first and second joints there are two 

 projecting spines ; these differ much in different indivi- 

 duals as to their length, slenderness, and direction ; some- 

 B 2 



