cv:.. 



a.z: 



c.v. 



FIGURE 11 



FIGURE 12 



FIGURES 11, 12 STEXTOR CAERULEUS (aFTER JOHXSOn). 



a.z.,^ adoral zone, b.p,, buccal pouch, c.v., c.v,,^ contractile vacuole, 

 d.a.z.,' distal extremity of adoral zone. ex. p., excretory pore of con- 

 tractile vacuole, f, f, frontal field. 1, 1,^ line of fission, mgn., 

 inejranucleus. o, o', mouth. }), p', peristome band, r.z., r,z.,^ rami- 

 fying zone. ^'eI'., velum. 



274 



