2io CLARKE. 



EXPLANATION OF PLATE XI. 



(Figures 21 to 26, inclusive, are mine. Figures 27 and 28 are from life, and by Mr. C. C Hayes.) 



Fig. 21. Ventral side. 



Fig. 22. Dorsal side of the same embryo. 



Fig. 23. From the dorsal surface. 



Fig. 24. Ventral view of the embryo shown in Fig. 23. 



Fig. 25. The ventral surface. 



Fig. 26. The same embryo from the dorsal side. 



Fig. 27. A drawing, made from life, of the dorsal surface of an embryo. 



Fig. 28. The same embryo from the ventral side. 



