Visually less sophisticated than later ads were... but if you'll take the time to read the portion below, I think you'll find that this is one of the most amusing Sea-Monkey ads ever... as it probably marks the last time that Sea-Monkeys are referred to as "underwater buffoons".

The entertaining text in this ad reads as follows:

Just Add Water - you've got "INSTANT LIFE"
Yes, it's the living truth! In only five minutes you will actually hatch a whole tumbling, playful, happy troupe of Sea-Monkeys that are even more fun than a zoo full of chattering, howling jungle monkeys! World's most amazing new pet, children and adults alike will laugh and thrill with wonderful excitement. Watch the comic antics of these fantastic underwater buffoons that are really alive. Any minute of the day or night, you'll see them chase one another in a playful game of tag. The loser gets caught by his tail and is spun in a dizzy circle. See the "showoffs" turn cartwheels of joy in the water... see the ticklish ones "scratch" each other's backs. Watch them swim singly or in ever-changing graceful formations, creating a live sea-circus.