Plate II. 



Fig. 8. Central nervous system of Tethys dactylomela (Rang). 

 cer. g., cerebral ganglia; ped. g., pedal ganglia; pi. g., 

 pleural ganglia ; hue. g., buccal ganglia ; c. p. con., cere- 

 bro-pedal connectives; c. pi. con., cerebro-pleural con- 

 nectives; c. b. con., cerebro-buccal connectives; pi. par. 

 con., right pleuro-parietal connective; pi. v. con., left 

 pleuro-visceral connective; p. com., pedal commissure; 

 p. p. com., parapedal commissure. 



The nerves from each ganglion are numbered ser- 

 ially as described in the text, and are distinguished by 

 the prefixed letter, b., c, pi, or p., indicating their repec- 

 tive ganglia, buccal, cerebral, pleural or pedal, x 10.5. 



