Smith. — Eyes of Puhnonate Gasteropoda. 



PLATE 1. 



Fig. 1. Median dorso-ventral section of the tentacle and eye; diagrammatic 

 X52. 



Note. — By an oversight (/. (dorsal) and v. (ventral) were interchanged 

 in this Figure. 

 Fig. 2. Photomicrograph of a gold-chloride preparation ; longitudinal section in 



plane at right angles to that of Figure 1. X 190. 

 Fig. 4. Single, depigmented cell-group. Compare Plate 2, Figure 14. 

 Figs. 3, 5, 6, 11, 12. Cross sections of sensory cell and surrounding pigment cells, 

 successively more proximal ; depigmented. 

 Similar section through base of rod. 



Similar to Figure 7 and through same cell-group, but 6| p. more distal. 

 Ketinal group from a large macerated eye. 

 Fig. 10. Single pigment cell from the same preparation as Figure 9. 



