130 COMPARATIVE ANATOMY CHAP. 



in than the buccal connective, a nerve (the subradular connective) rises and runs 



n ^ , 



,0 



FIG. 111. Diagram of the nervous system of Chiton siculus (after Bela Haller). The mantle 

 removed on the right side. In the centre and to the left the upper part of the foot removed, to 

 expose the pedal nervous system. F, Foot ; K, last gill; A, anus ; 0, upper, U, lower half of the 

 resophageal ring ; 1, '2, nerves of the cesophageal ring ; c, connective to the anterior visceral ganglia ; 

 p, connective to the ganglia of the subradular organ n (above on the left) ; Es, pleurovisceral and 

 pedal cords ; mn, gastric nerve ; So, point of attachment of the sphincter oris ; n (below on the 

 right), ni, tt2 nephridial nerves ; m, pallial nerves ; p (to the right below), cardial nerves ; v, a 

 dorsal nerve of one of the pedal cords. The commissures between the pedal cords are seen, and 

 the nerves running outwards from the latter. > 



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 forward and inward to the subradular ganglion. This ganglion lies in the sub- 



