25 



I'ior adductor. 



The ulimentary canal is ali'eady hi,";hly specialized 

 '■''"'■'s. 1,24). A comi)aratively lonf;; oesophar^is < <- . o . ) 

 loads into the stomach, from which a sinrjle lar o livor 

 vesicle projects on either side. The sheath j. ..iiO crys- 

 talline style projects from the posterior ventral portion 

 of the stomach on the midline. The intestine leaves tlie 

 stomach from the rif^ht side, anteriorly, and the caeci.im 

 peculiar to the Pholadacea is present as a hemispherical 

 rudiment on the right side, just postei-ior to the opening 

 of the intestine. 



The nervous system of the larva (figs'. 2,59) is 

 hi.f^ly specialized. The f5anglia are comi-osed of ganglion 

 cells and the connectives contain only nerve-fibres. On 

 eitiier side the pleural (pi) ganglion is still separate 

 from the cerebral (c). From the pleural a connective pas- 

 ses to the visceral, ana from the cerebral, one to the 

 pedal. 1 think a pleura-pedal connective is also present, 

 but this I am not aule to state positively. The two pe- 

 dal ganglia are closoly fused, v.-liile the visceral are wide 

 apart. 



The kidneys (k. fir-. 2) consist of large vacuolated 



