5 , Gk; a are a the coral used was without the cil scum and had noe count above background on the survey meter, The fish in #6 has likewise fed regularly. Aquaria #1, 3 and 4 were retained as controls, Six larger aquaria, 12" x 24" x 16", were set up originally but were not as satisfactory as the setup for the smaller aquarina described above. The large aquaria are now being used as supply tanks for fish and other marine animals as well as for an irradiation mortality experiment with the marine snail, Thais lamellosa, Qn April 14th mix more of the smaller aquariawere delivered and were set up in the same manner as those for the flatfish. Tide Pool johmnies, a soulpin, Oligocuttus maculosus, were placed in these aquaria, They have not yet been used experinentally but seem well adapted to their new environment, The experiment in aquaria #2 and #5 will be continued until it is believed that the fish is about to die, At that time tissues will be praserved for histological studies, Project VI. Observations on the amphipods were discontinued because of high mortalities among the controls. Marine snails, Thais lamellosa, A report will be submitted. that had been surviving well in 15-gallon aerated aquaria, were individually marked with a number and X-rayed on April 2. Exposures given, and numbers of snails irradiated, weret 10,000 r —- 23 S000 r - 63 2000 r=93 500 r= 93 and 200 r- 9, 1250 r ~ 9; After 3 weeks the mortalities anong irra- diated and control snails were approximately equal. The snails spawned in the aquaria, attaching their ogg cases to rocks, shells, and especially to the glass aides of the aquaria. When only a few egg oases were deposited, their positions were recorded along with ve DosARCHIVES