Bull. U. S. B. F., 1930. (Doc. 1097.) 
Figure 8. — Actinonais carinata, river mucket, natural size. Living animal, with one valve of the shell removed to show 
foot in a completely retracted condition. Compare volume of foot in this with the expanded foot in preceding figures. 
The line of demarcation between foot and visceral mass is clearly shown 
