308 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
EXPLANATION OF PLATE L. 
Figs. 35 and 36. Views of the under sides of the heads of adult females of the common sturgeon, 
showing the relative position of the barbels and mouth, with its undistorted fleshy mar- 
ginal processes as seen in the recently hilled animal. From photographs. 
Fig. 37. View of the under side of the head of an adult male of the common sturgeon, showing the 
areolation on the under side of the snout in front of the mouth, the areolae being sensory 
tactile areas supplied by the fifth nerve. From a photograph. 
