Pbbntiss. — Otocyst Crustacea. 



PLATE 5. 



All Figures are of lobster larvce. In Figures 23 antl 25 dorsal is up, and anterior 

 at the right ; in Figure 24 dorsal is up and lateral is at the riglit; anterior is at 

 the right in Figure 26. 



Fig. 23. Parasagittal section through the antennule of the third larva. X 168. 

 Fig. 24. Transverse section through the posterior part of the right otocyst in 



fourth larva. X 168. 

 Fig. 25. Parasagittal section of the same. X 125. 

 Fig. 26. Diagrammatic dorsal view of floor of right sac dissected out to show 



arrangement of the hairs and their innervation. Methylen blue. 



X 168. 

 Fig. 27. Developing hairs of the otocyst in the third larval stage. X 600. 



