Plate 12. 



Fig. 60. Center of a young Cesium veneris, 84 mm. long. Tortugas, 

 Florida, May 25, 1907. 



Fig. 61. Center of a mature Cesium veneris. Tortugas, Florida, 

 July 4, 1907. ad, adradial vessels; /, funnel; //, axial 

 funnel-tube; g, paragastric canals; i, interradial canals; 

 mti, muscle fibers: si, subtentacular meridional canals; 

 sio, stomodffium; sv, subventral meridional canals; i, 

 tentacular canals; ten, tentacle-bulb; ts, opening of ten- 

 tacle-sheath. 



Drawn from life, by the author. 



