68 KINGSLEY. 



DESCRIPTION OF PLATE VI. 



Fig. 20. A part of Fig. 19 more enlarged, showing the process of delamination. 



Figs. 21-26. Successive stages of the germinal area previous to the formation of 

 the appendages. See the text. 



Fig. 27. Budding of the legs. 



Fig. 28. An unusual form of embryo, appendage I. not yet formed. 



Fig. 29. The germ vievi^ed as a transparent object. Appendages I. -VI. present. 

 The nervous system is covered by circularly arranged nuclei, the centres of rapid 

 cell proliferation. Outside the germinal area are seen («) segmentally arranged 

 structures of possibly glandular or sensory functions. 



Figs. 30, 31. Two surface views illustrating the transfer of the mouth backwards, 

 accompanied by the formation of the stomodseum. 



Fig. 32. Appearance of the embryo before the distinction of cephalothorax and 

 abdomen is prominent. 



Fig. 33. Side view of a late embryo, the abdomen differentiated. 



Figs. 34, 35. Dorsal and ventral views of the last larval stage before the appear- 

 ance of the telson. R. Takano, del. 



Fig. 36. Longitudinal section of a stage about like Fig. 21, showing the primitive 

 cumulus and its central spot. 



Fig. 37. Early stage of mesoderm formation. 



Fig. 38. Late stage of same, showing primitive groove and lateral connection of 

 mesoderm and ectoderm. 



Fig. 39. More enlarged view of primitive groove. 



