418 



GOMP AMATIVE ANATOMY 



CHAP. 



to the body) a gill consisting of numerous integumental folds, 

 arranged like the leaves of a book. 



Fin. 2S4. — Limulus polyphemus, young specimen from the ventral side (after Packard). 



The leaf-like feet serve for swimming as well as for lireathing. 

 A sternal endoskeleton is present. 



