Wonder Woman #128

“When Wonder Woman dives underwater to look for a hidden grotto, she comes across Mer-Man who asks her to the Mermen's Ball. Mer-Man's invitation is interrupted when he gets trapped in a giant clam while Wonder Woman herself becomes entangled in living seaweed. Both are saved when Diana uses her tiara to shatter the clam and cut through the seaweed's fronds. From Wonder Woman #128, 1942.”