28O JOHANNA M. DIECKMANN. 



PLATE III. 



FIG. 19. From the same animal as Fig. 18, Plate II.; taken at a more cephalic 

 level; showing spermathecal tubules growing out from the area of highly nucleated 

 epithelium. (X33-) d.s., top of dorsal slit, d.e., one fold of dorsal elevation. 



FIG. 20. Dorsal elevation and spermathecal region from an animal of 10.7 cm. 

 (X 33.) d.s., top of dorsal slit, d.e., one fold of dorsal elevation. 



FIG. 21. Same animal as Fig. 20; taken at a more cephalic level. ( X 33-) 



FIG. 22. Dorsal elevation and spermatheca of animal of n.o cm.; showing 

 tubules which have been turned latero-ventrad; in the center the narrow necks 

 of tubules which terminate farther caudad. (X33.) d.s., top of dorsal slit. 

 The cloaca is greatly distended, therefore, the two folds of the dorsal elevation 

 are spread widely apart. 



FIG. 23. From the same animal, taken at a more cephalic level; showing the 

 Y-shaped portion of the common tube communicating with the dorsal slit; and 

 irregular lumina forming in the cell mass above the common tube. ( X 33.) 



FIG. 24. Cloaca and spermatheca of an animal of 11.2 cm.; showing the two 

 limbs of the dorsal elevation in the dorsal cloacal wall; above, the two branches 

 of the common tube, with which tubules communicate. ( X 33-) 



FIG. 25. Dorsal elevation and spermatheca of the same animal, taken cephalic 

 to the level of Fig. 24; showing the distal part of the common tube, with an H- 

 shaped lumen. ( X 33.) 



FIG. 26. Dorsal elevation and spermatheca of same animal; taken at a level 

 cephalic to that of Fig. 25; showing expanded proximal end of common tube 

 communicating with dorsal slit. ( X 33.) d.s., top of dorsal slit. 



FIG. 27. Diagram of median sagittal section of cloaca of young animal; in 

 dotted lines the outline of an adult cloaca, relatively reduced in size. Arrows a 

 and b indicate unequal growth of dorsal and ventral walls, which results in shifting 

 spermatheca cephalic to vent and turning tubules caudad. Small arrows indicate 

 overgrowth of dorsal wall, which elongates common tube, and produces dorsal 

 elevation and diverticulum. 



