200 



COBLENTBRATA. 



ex 



FIG. 159. Sense organs and adjacent organs, I of Cestus veneris in side view (from the stomach 

 plane) x 100, II of Eucharis multicornis from above x 120 (after Chun), a sense organ ; 

 gl bell ; / the four springs ; ri 1 to % 8 the eight ciliated grooves with their cilia ci, and their 

 plate-like expansions at the base of the springs pi and pi' ; k granules ; ot otoliths ; ot l otoliths 

 in process of formation ; p edge of polar plate ; pf middle part of polar plate (polar field) ; 

 mu (in II) muscular fibres running beneath the ciliated grooves ; me circular muscular fibres ; 

 mu (in I) longitudinal muscles of the funnel-vessels ; v funnel-vessel ; gg branching of a 

 funnel-vessel into the ampullae ; ex aboral excretion pores. 



