>Mx. 



O ^s?>i^- 



.■i__i-^ft. 



A B 



Fig. 194. Anterior part of nervous system in A, Lumhricus. After Borradaile. 

 B, Hirudo. After Leydig. The brain m both consists of a single dorsal pair 

 of ganglia belonging to the prostomium. In Lumbricus the subpharyngeal 

 ganglion {shp.) and lower part of the circumpharyngeal commissures give 

 off nerves to segments i (peri.) peristomium, 2, 3 and so belong to three 

 segments. In Hirudo the subpharyngeal mass consists of four (or five) pairs 

 of ganglia fused together, e. eyes ; M.c. mouth cavity ; j. jaws ; pr. prostomium ; 

 ph. pharynx (with network of visceral nerves); so. sense organs. 



Fig. 195. Glossiphonia as example of the Rhynchobdellidae. Dorsal view. 

 an. anus; cr. crop (black); oe. oesophagus; int. intestine (stippled); pb. pro- 

 boscis ; ps. proboscis sheath ; rh. rhynchodaeum ; rm. rectum ; sa.gl. salivary 

 glands. 



