PLATE XVII. 



Fig. S4. — Longitudinal section through the anal region. Showing the ganglion and its relation to the lateral nerve 



cord. ,\ Ob. X 4 Oc. Camera. X 450. 

 Fig. 85. — Transverse section through the region of the anal papilla. Showing the relation of the nerve ring to th» 

 lateral nerve. J Ob. X 4 Oc. Camera. X 450. 

 148 



