ever be ommivorous, since a similar Pacific Coast species is known to stun prey with the violent anapping of a specialized claw, hence the name, “pistol shrimp.” It is difficult to conceive how, living encased in a cylinder of highly enmeshed filaments of algae, it could feed on anything larger than very small plankton, if that, in addition to the algae. The simi- larity of the specific activities found in the viscera of the shrimp and in the algae, @s shown below, indicate the effect of food habit upon the radioactivity of the digestive trac:. Rigili Runit d/m/g wet Shrimp muscle viscera Algae a/m/g wet 15,000 7,000 110,000 31,000 210,000 36,000 - 103 -