PLATE 15 

 Polyorchis penicillata 

 Fig. 8. Ocelli from the same medusa showing the distribution of 

 pigment on different tentacles. The darker spot is the brown pigment 

 at the center of the ocellus. X 14. 



Fig. 9. Pigmentation of a well-developed ocellus. The darker cen- 

 ter is the brown pigment of the ocellus. The red pigment extends peri- 

 pherally from this but especially upward upon the bell and downward 

 upon the tentacle. X 60. 



Fig. 10. A single large red pigment mass. X 666. 



Fig. 11. Pigment-bearing cells of the ocellus. 



a. Isolated epithelial cells with red pigment. 



b. Epithelial cell without pigment. X 1300. 



Fig. 12. Isolated ganglion cells from the epithelium of the tentacle 

 near the ocellus showing interlacing of ganglionic processes with the 

 muscle fibers. X 1300. 



Fig. 13. Same showing distal branching of ganglionic processes. 

 Fig. 14. Isolated nerve cells from the base of the ocellus of bipolar 

 and multipolar types. 



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