688 A NKW ENDOPAKASITIC COPEPOD. 



Fig.25. — Transverse section at the level of the posterior end of the alimen- 

 tary canal(a^. )• 



Fig.26.— Two cells from the digestive(?) gland related to tlie second com- 

 partment. 



Fig.27. — Transverse section at the level of the external orifice of the vas 

 deferens(ap. ) and the vesicula semiiialis(?;.s.). 



Fig.28. — V^as deferens in transverse section. 



Fig.'29. — Epithelium of the oviduct. 



Fig.30. — I'ortion of the section drawn in Fig.27, under higher magnification: 

 vas., vas deferens. 



Fig.31.— Transverse section at the level of the vulva (?•.) on one side: 

 s.yL, slime-gland. 



Fig.32. — The region of vulva(y.) Mas., plain muscle-bumlles. 



Plate Ixx. 



Fig.33. — The two-celled embryo, transverse section. 



Fig 34. — The four-celled embryo, transverse section. 



Fig. 35. — The sixteen-celled embryo, transverse section. 



Fig.36. — The sixteen-celled embryo, longitudinal section. 



Fig.37. — The sixteen-celled embryo, longitudinal section. 



Fig. 38. — The thirty-two-celled embryo, transverse section. 



Fig.39. — The gastrulation period of development, longitudinal section. 



Fig. 40. The gastrulation period of development, transverse section. 



Fig.41. — Longitudinal coronal section of the late gastrula. 



Fig.42. The very early nauplius(A', anteiinule; A", antenna; 7nu., man- 

 dible; mes., mesoderm; g., primodial germ-cell). 



Fig.43 — A more advanced nauplius(e. , eye). 



Fig.44.— The nauplius(/6r., labrum). 



Pig 45. The nauplius, nearly median coronal section (oc, retinal celh ; 



br., brain; nph., larval kidney). 



j'ig.46. The nauplius, median sagittal section (cJtd., eudoderm; mus., 



skeletal muscles). 



