EXPLANATION OF PLATES 



Figure 1 was drawn with the binocular microscope under low magnification. 



Figures 2 to 22 were drawn under higher magnification ( X 10 oculars, 40-mm. 

 and 22-mm. objectives). Figures 1 to 3 were taken from the younger veil; 

 figures 4 to 22 were drawn on successive days from the most advanced specimens 

 among the embryos and larvae of the older veil. The number of the day refers 

 to number of days after capture of the veils. Since the younger veil was 

 probably spawned on the morning of the same day that it was found (p. 3), 

 it is evident that the day number gives the age for that veil from fertilization 

 for the temperatures given. The embryos of the older veil are about a day 

 older from the time of fertilization. 



PLATE 1 



EXPLANATION OF FIGURES 



1 Portion of younger veil immediately after capture; embryo in capsules 

 in natural position. 



2 Embryo of younger veil immediately after capture. 



3 Embryo of younger veil one day after capture; dorsal view. 



4 Embryo of older veil one day after capture; ventral view. 



5 Embryo one day after capture; ventral view. A few hours older than 

 embryo shown in figure 4. 



6 Embryo, second day; ventral view. 



7 Larva, second day; ventral view. 



8 Larva, third day; ventral view. 



9 Larva, fourth day; ventral view. 



17 



