Plate XVI 



Fig. 76 a, Corneal facet and upper end of cone from fully regenerated ommatidium; b, fully regener- 

 ated rhabdom a and b both taken from regenerated hermit crab eye shown in Fig. 15. Ommatidia of 

 hermit crabs much more slender than Palaemonetes ommatidia. X 900. 



Fig. 77 Hermit crab, sixty-seven days. Section through brain and proximal end of heteromorphic 

 appendage. Shows continuity of optic ner\'e and ner\'e trunk of appendage. Slightly diagrammatic. 

 X 125. 



Fig. 78 Section through distal end of heteromorphic appendage, showing strands of fibers sn.f. 

 extending to the sensory hairs, and groups of sensory cells, sn.c. X 125. 



Fig. 79 Detail drawing of small part of section shown in Fig. 78. Shows sensory cells and fibers 

 sn.f. in connection with bases of two sensory hairs. X 750. 



