212 STUDIES IN EVOLUTION 



exopodite fringed with setse, and developed into a swimming 

 organ; coxopodite with gnathobase. 



Appendages of the pygidium, true phyllopodous limbs. 



Hypostoma. 



Mouth between hypostoma and metastoma. 



Metastoma, a convex crescentic plate, with side lappets. 



Anus in median line, near ventral extremity of pygidium. 



