80 



Journal lit Knt(imol()f;y and Zoology 



lobe of the mantle. From the anterior angle a ventral pallial nerve 

 soon branches into two, one for the dorsal lobe of the mantle and 

 one for the corresponding adductor muscles. It is probable that 

 these nerves also go to the muscles and viscera. In the ventral re- 

 gion is a ple.xus formed by the ventral pallial nerves. In the 

 mantle the pallial nerves form a plexus with ganglion cells. 



There are no positive organs of .sense ; there are neither eyes 

 nor otocysts. Probably the margins serve as organs of touch. The 

 cirri are probably for tactile sense, possibly olfactory. They have 

 a rich nerve plexus. 



Stomach papillae Joubin, 1886-92, suggested as gustatoi-y, and 

 the terminal papillae of the mantle Sollas, 1887, believed had a 

 tactile function. 



In Ecardia, Delage and Herouard give a separate account. A 

 single pair of ganglia are situated very low and at the external 



14-1^ ^}- 



P'ifc. 2.T. Nervous System of Brachiopoda. A. Diagram of the nervous sys- 

 tem from the ventral side showing the ganglion and chief nerves 

 after Blochmann. Much modified. B. Diagram of the nervous sys- 

 tem of n brachiopod, after Brammelon. C. Position of the nervous 

 system shown in position. Diagrammatic. D. Diagram of LinguUt 

 showing ganglia in dark. E. General plan of the nervous system. 

 F. Plan of the central nervous system. G. Nerve plexus. 



