28O WILLIAM A. KEPNER. 



EXPLANATION OF PLATE II. 



FIG. 7. Undischarged nematocyst with its vacuole filled by cytoplasm. It 

 lies near the ectoderm, E. Camera lucida drawing. X 1,500. 



FIG. 8. Section next to that represented in FIG. 7. Shows the nucleus, N, 

 of cell associated with the nematocyst. Camera lucida drawing. Xi.soo. 



FIG. 9. Partially discharged nematocyst. E, ectoderm; M, basement mem- 

 brane of endoderm. Camera lucida drawing. X 1,500. 



FIG. 10. Partially discharged nematocyst. TV, nucleus of cell associated with 

 nematocyst. Camera lucida drawing. X 1,500. 



FIG. ii. Nematocyst discharged approximately parallel to the surface. E, 

 ectoderm; M, basement membrane of endoderm. Camera lucida drawing. X 1,500. 



FIG. 12. Grappling nematocyst, partially discharged. E, ectoderm, M, 

 basement membrane of endoderm. Camera lucida drawing. X 1,500. 



FIG. 13. Grappling nematocyst, partially discharged. An attending cell or 

 cnidophage is shown within the vacuole within which the nematocyst lies. Camera 

 lucida drawing X 1,500. 



