Prentiss. — Otocyst Crustacea. 



PLATE 10. 



All Figures are of Carcinus ; anterior is up in Figure 55. 



Fig. 49. Group liair. X 600. 



Fig. 50. Transverse section through the sensory cushion of the liook hairs. 



X 168. 

 Fig. 51. Hook hair. X 600. 

 Fig. 52. Portion of outer flagelluni of antennule, showing the bases of olfactory 



hairs and tlieir innervation. X 95. 

 Fig. 53. Thread hairs and their nerve elements. Methylen blue. X 95. 

 Fig. 54. Tip of thread hair. X 1300. 

 Fig. 55. Nearly frontal section, inclining dorsal and forward, through both anten- 



nules and brain. X 25. 



