EXPLANATION OF THE PLATE. 
ad. org., adhesive organ. 
a. p., auditory pit. 
b. a., branchial area. 
b. a. 1., first branchial arch. 
b. c., body cavity. 
bt., button (prae-oral gut). 
cr., crescent (fundament of prae-oral gut and adhesive organ). 
h. a., hyoid arch. 
m. a., maxillary arch. 
st., stomadaeum. 
th., thickening of neural crest. 
Fic. 1.—Dorsal view of an early embryo of Amia, showing the first 
stage of the adhesive organ as part of a crescent-shaped elevated area. 
The line a-b indicates the plane of the section shown in text figure B. 
Description in text, p. 470. Drawn from a photograph. X 20. 
Fic. 2.—Dorsal view of an embryo of Amia, showing the second stage 
of the adhesive organ, as a pair of protuberances with the button between 
them. Description in the text, p. 473. Drawn from a photograph. X 20. 
Fic. 3—Ventral view of an embryo of Amia with the adhesive organ 
in the third stage. Description in the text, p. 478. Drawn from a photo- 
graph. X 20. 
Fic. 4—Embryo of Amia at about the time of hatching. The embryo 
is between six and seven mm. long. Ventral view. Description in the 
text, p. 482. Drawn from a photograph. X 20. 
