Leiotealia nymphcea (figs. 1-5). 



Fig. 1. Transverse section through the oral disk. A, Oc. 2. 



Fig. 2. Radial section through the anterior end of the body, the wall with upper 

 and lower [ms') circular muscles, and the oral disk with a tentacle. Unscr. A, Oc. 2. 

 For I in the lettering of the plate read t. 



Fig. 3. Transverse section through the septum at about one-third the height of the 

 animal, passing perpendicularly through the parietobasilar muscle and longitudinal muscle. 

 A, Oc. 1. 



Fig. 4. Half a transverse section of the upper circular muscle. C, Oc. 1. 



Fig. 5. Septum ; natural size. 



Dysactis crassicornis (figs. 6-12). 



Fig. 6. Transverse section through a septum. A, Oc. 1. 



Fig. 7. Transverse section through the upper end of the wall. Unscr. A, Oc. 2 

 diminished two-thirds. 



Fig. 8. Part of a transverse section through the circular muscle, more highly mag- 

 nified. D, Oc. 1. 



Fig. 9. Section through the circular muscle parallel to the course of the fibrillar. 

 A, Oc. 2. 



Fig. 10. Transverse section through the oral disk of an old animal. Unscr. A, Oc. 2. 



Fig. 11. Transverse section through the oral disk of a young animal. Unscr. A, 

 Oc. 2. 



Fig. 12. Septum ; natural size. The circular muscle appears rather too large in the 

 drawing. 



