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BULLETIN OF THE UNITED STATES FlSli COMMISSION. 
EXPLANATION OF PLATE XLI 
Pig. 16. Larval sterlet, loug. The median tiu-l'old is being differentiated into the caudal, dorsal, 
and anal. The sense capsules, nose, eye, and ear more developed, and the barbels are more 
elongated. The gill filaments are exposed beyond the margin of the operculum. The yelk 
is nearly absorbed. After W. K. Parker. 
Fig. 17. Head of larval sterlet of the same length as the individual of the preceding figure, but dis- 
sected so as to expose the cartilages of the jaws and gills of one side. The palatopterygoid 
and Meckel’s cartilage are seen to support teeth. After W. K. Parker. 
