254 OILMAN A. DREW. 



PLATE XXI. 



Fig. 23. Nervous system as seen from in front and a little to one side. Natural 

 size. (Diagrammatic.) 



apn, anterior pallial nerve; bn, branchial nerve; cc, cerebral commissure; eg, 

 cerebral ganglion ; epc, cerebro-pedal connective ; cfn, circumpallial nerve ; cvc, 

 cerebro-visceral 'connective; of, otocyst ; pg, pedal ganglion ; pn, palp nerve ; ppn, 

 posterior pallial nerve ; vg, visceral ganglion. 



