Fig. 274. Diagram of the correlations of the muscular septa and of the 

 chitinous armature of the attaching discs of Monocotylidae. A- -Hypothetical 

 form; B--Disc of Monocotyle and Heterocotyle; C--Disc of Dasybatotrema 



and Calicotyle; D--Disc of Merizocotyle; E- 

 F. 



-Disc of Thaumacotyle; 



■Disc of Empruthotrema; the disappearing septa are indicated by a 

 dotted line. 



434 



