EXPLANATION OF PLATE XX. 



FIGURE 101. Loligo pallida, (p. 635 ;) dorsal view, about one-third natural size. 

 101. The same ; the &quot;pen &quot; dorsal side. 

 102. Loligo Pealii ?, (p. 635 ;) a cluster of the eggs. 

 103. The same; an embryo just before hatching, much enlarged; a , a&quot;, a 1 &quot;, 



a&quot; , the right &quot;arms 7 belonging to four pairs; c, the side of the head; 



e, the eye ; /, the caudal lins; h, the heart ; ?, the mantle in which 



color-vesicles are already developed and capable of changing their 



colors ; o, the internal cavity of the ears ; s, the siphon ; i/, the portion 



of the yolk not yet absorbed. 

 104. The same; an embryo in an earlier stage of development, more highly 



magnified ; the letters are the same as before. 

 105. The same; a young specimen, recently hatched, found swimming at the 



surface, dorsal view. 



(Figures 103, 104 are camera-lucida drawings made from the living specimens, by A. E. Yerrill; 

 all the others were drawn from preserved specimens, by J. II. Emertou.) 



